By Sandra Vogel | March 21, 2016 -- 10:08 GMT (03:08 PDT) Editors' rating 8.0 Excellent $1,499.00 Average user rating 9.0 2 user reviews Pros Tough construction Superb 13.5-inch screen Screen detaches for tablet-mode use Discrete Nvidia GPU (on some models) Surface Pen is a pleasure to use Supports Microsoft Surface Dock Cons Clever but not entirely successful hinge system Poor tablet battery life Relatively heavy Expensive Microsoft's original Surface tablet made its debut in late 2012. Since then we've seen it evolve into the Surface Pro 4, which was unveiled late last year -- along with an unexpected 'one more thing' item in the shape of the Surface Book, a 2-in-1 laptop/tablet hybrid with a detachable screen. With a starting price of £1,299 (inc. VAT), or $1,499, this is not a device for the cash-strapped individual or budget-conscious IT manager. But does it justify the price? The 13.5-inch Surface Book is powered by 6th-generation Intel Core i5 or Core i7 processors. There are batteries in the screen/tablet and keyboard sections; most models also feature a discrete Nvidia GeForce GPU in the keyboard unit. Images: Microsoft Microsoft has set itself a high bar with the Surface Book, which like its Surface Pro stablemate is a premium product. Its two-piece design is common in the Windows world, but is something that Apple -- which prefers to keep its tablet (iOS) and laptop (OS X) lines separate and distinctive -- has not yet attempted. By coming up with a detachable screen, Microsoft is saying 'we can do a great large-format tablet and a great laptop -- at the same time'. Let's see. The Surface Book's look and feel is somewhat austere. The grey magnesium alloy that covers almost every visible part of the chassis and keyboard has a distinctive matte finish and light-absorbing properties. The keys disappear into their surroundings because they share the same colouring and material -- the effect is heightened if you're using the backlight that shows through the keys' symbols. This minimalist design doesn't do it for us, but others will doubtless love it. The Surface Book's Dynramic Fulcrum Hinge unfolds as you open the device in laptop mode. This design, and the main battery in the keyboard section, helps to keep the system reasonably well balanced. Image: Microsoft One chassis feature that stands out is the hinge between the screen/tablet and keyboard sections. The main problem that besets detachable-screen laptops is top-heaviness, because the screen section contains most of the computing hardware. Microsoft's solution is a multipart hinge -- called the Dynamic Fulcrum Hinge -- that unfolds when you open the Surface Book to add what we measured as about 15mm of table-touching surface to the base. This moves the laptop's balancing point so that it's less likely to topple backwards when you prod at the touchscreen. It isn't a perfect solution: gentle screen sweeps and taps are accommodated with no bother, but more vigorous prods can cause the system to tip backwards. As you'd expect, this is more likely to happen when you're tapping the top of the screen than the bottom. Moreover, the non-grippy magnesium base means that the Surface Book can move around on a shiny desk or table when you're using the touchscreen. You can detach the screen and re-attach it facing away from the keyboard -- to use in 'presentation' mode, for example. Image: Microsoft As with other convertibles, you can use the Surface Book in different modes, with the screen either facing away from or laying flat on the keyboard, for example. But to achieve these you need to remove the screen and replace it facing outwards. This is much a more fiddly process than the rotating screen seen in devices like Lenovo's Yoga 900, and we'd probably find it too much hassle to use regularly. The other drawback with the Dynamic Fulcrum Hinge is that you can't push the screen back very far in laptop mode, so there's no option to lay the screen anywhere near flush with a table or desktop. The Surface Book is on the heavy side at around 1.5kg, but its footprint, at 31.23cm wide by 23.21cm deep, is perfectly acceptable for a laptop with a 13.5-inch screen. For the record, the Surface Pro 4 has a footprint of 29.21cm wide by 20.14cm deep. The hinge design adds a bit of height to the back of the chassis, so that when closed the Surface Book is relatively thick at the back -- 2.28cm, tapering to 1.3cm at the front. The design of the Dynamic Fulcrum Hinge means that there's a gap between the screen and keyboard sections when the Surface Book is closed. Image: Microsoft This tapering creates a width-ways gap through the Surface Book when closed that stretches pretty much all along its length, with a maximum opening of about 5mm. That's ample room for detritus in your bag to work its way between screen and keyboard -- at best making the insides dusty, at worst causing scratches or other damage. For all its good looks, the Surface Book's keyboard is a little disappointing in use. Travel is a touch less than we find optimal, the keys are a little bit 'clacky', and the overall feel falls just short of premium quality. The trackpad, on the other hand, is great: it's large, very responsive and feels smooth beneath the fingers. More expensive Surface Book models incorporate a custom-built discrete Nvidia GeForce GPU. This sits in the base, while the Intel HD Graphics 520 GPU is in the screen section, integrated with the CPU and available for use in tablet mode. There's no restriction on the apps you can use when undocked, although you'll obviously get less graphics performance without the discrete GeForce GPU in operation (see below). When you want to remove the screen you have to press a dedicated 'undock' key which initiates a power-down of the GeForce chipset. There's a short wait while a light on the key turns from red to green and there's also a click which indicates that the 'musclewire' system locking the screen and keyboard together has been released. You get a few seconds to remove the screen, after which the green light goes out and the lock is reset. Redocking doesn't require use of the button. When connected, the two sections are held together with incredible force: there's no chance they'll come apart while you're carrying the Surface Book around. The Surface Book's 13.5-inch, 3000x2000-pixel screen is one its best features. Image: Microsoft The 13.5-inch PixelSense screen is superb, its 3,000-by-2,000-pixel resolution (267ppi) delivering sharp, clear and bright images and text. Viewing angles are excellent, and the 3:2 aspect ratio hits a sweet spot for both document creation/editing and entertainment. The screen is wide enough to have two working documents open side by side, and when undocked the relatively large tablet becomes an excellent vehicle for consuming media in both landscape and portrait orientations (Microsoft call the latter 'Clipboard' mode). The tablet section feels remarkably light and manageable, too. You can customise the Surface Pen's top button settings in the Surface app. Image: Sandra Vogel/ZDNet As well as using the keyboard and your fingers to interact with the Surface Book, you can use the Surface Pen. This stylus, which adheres magnetically to the left side of the screen, will be familiar to users of the Surface Pro 4. The Surface Pen looks and feels like a real pen and is comfortable to grip. It recognises 1,024 pressure levels, and you can customise it by swapping the standard tip for softer or harder, finer or thicker options depending on your intended use. What we like most, though, are the shortcuts you can implement by pressing the opposite end of the pen. A single click launches OneNote, for example, while a double click takes a screengrab into OneNote and a single press-and-hold launches Cortana. You can customise these functions in the Surface app. If you're thinking of using the Surface Book for presentations then you'll be pleased to know that we found speaker quality good and volume loud, though the reflective screen may prove an irritant in some situations. Microsoft has produced four versions of the Surface Book for purchase off the page in the UK as we write, variously sporting 6th generation Core i5 and Core i7 processors with SSD storage ranging from 128GB to 512GB. The price for the entry-level Core i5/8GB RAM/128GB SSD model is £1,299 (inc. VAT). We were sent the top-of-the-range £2,249 (inc. VAT) model, which has a 2.6-2.8GHz Intel Core i7-6600U processor, 16GB of RAM and a 512GB SSD. Business users will search in vain for a fingerprint sensor on the Surface Book. Instead, Microsoft provides 3D face recognition via Windows Hello and the 5-megapixel front camera (there's also an 8-megapixel/1080p camera on the back of the tablet). There's a fairly minimal selection of ports and slots. The keyboard section houses a pair of USB 3.0 ports, an SD card reader, a Mini-DisplayPort and the Surface Connect power connector. The tablet section only offers power and volume buttons, and a 3.5mm headset jack. There's a USB port in the charge unit, so you can charge another device -- such as your phone -- if necessary. If you need Ethernet or further DisplayPort or USB expansion, you'll need to invest in the optional Surface Dock, which costs £164.99 (inc. VAT). Performance & battery life Our top-end 2.6GHz Core i7/16GB RAM Surface Book with discrete Nvidia GeForce graphics was extremely responsive in general use, and delivered impressive benchmarks. Here's how it compares to a Surface Pro 4 powered by a 2.5GHz Core i5 with 8GB of RAM on Primate Labs' Geekbench 3 test: Image: ZDNet To investigate the contribution of the discrete Nvidia GeForce GPU in the keyboard section, we ran Maxon's Cinebench R15 OpenGL benchmark in laptop (with Nividia discrete GPU) and tablet (with Intel integrated GPU) modes: Image: ZDNet With the discrete Nvidia GPU in play, the Surface Book performs 60 percent better, so if you're going to run any graphically demanding applications, make sure you're in laptop mode. As previously noted, the Surface Book has two batteries -- an 18Wh unit in the tablet and a 52Wh unit in the keyboard, giving a total of 70Wh in laptop mode. Microsoft says you'll get up to 12 hours of video playback using both batteries, or three in tablet mode. The larger battery in the keyboard section is drawn on first, so that the tablet retains independent power for as long as possible. Our power consumption tests support Microsoft's battery life estimates, so long as you're running moderately demanding workloads and don't push the high-resolution screen's brightness up too far. With the CPU almost fully utilised and screen brightness at 100 percent, we measured the laptop's power draw at 28W, which if sustained would only last for 2.5 hours. You'll also need to learn to think of the tablet as something you take away from the keyboard occasionally rather than a device that can be self-sufficient for long periods. Conclusion Microsoft's Surface Book isn't a tablet-plus-keyboard combo. The high-quality keyboard section houses most of the battery and (in most models) a powerful discrete GPU. That makes the Surface Book a laptop with a detachable screen rather than a tablet with an attachable keyboard. While we admire the Surface Book's design and build quality, there are some shortcomings. The novel hinge system is not without its issues, for example, and battery life for the tablet could be better. The Surface Pro 4 may be a better choice if you want more emphasis on the tablet side of things, and there are plenty of more affordable convertible laptops you could consider.