...at the Best Buy. I'm more interested in the i5 but this is what they had. (Edit... this actually turned out to be an i5 4GB as noted in comments below, the store simply had it labelled incorrectly) The keyboard is amazing. It's so much better. Compared to the new keyboards on the new thin Macbooks---well lets just say in a side by side comparison it makes Apple's typing experience look like a joke. The touchpad is much, much better than that of the S3. The extra surface area and change in materials makes a big difference. The click on the touchpad is much better as well. It all feels better than any Macbook key/touchpad interface that I have used before. The keyboard has a printscreen button which is nice... I do not have a SP3 but looking over at one of the demo units, it looks like SP3 didn't have that. Only issue I encountered playing with it for an hour was that the touchpad occasionally did not respond until I would disconnect and reconnect the keyboard. Early pre-release bugs? No power in the pen... typical Best Buy. I could not try that out. The display is excellent, but I don't think worth the upgrade over the S3 unless you want to upgrade for the pen input improvements. I did notice it trying to auto adjust brightness levels somewhat erratically when scrolling through a webpage in Edge. Seems like another pre-release bug. I tried downloading some apps from their app store--one thing that is immediately apparent is that I suspect a bunch of app makers will need to redesign parts of their apps for the fact that SP4 doesn't have the windows button on the front glass bezel anymore...there were a few apps which once into fullscreen with the keyboard detached, there was no apparent way to leave fullscreen mode short of rebooting the device... ...yet rebooting is incredibly fast... practically instantaneous. The SSD is very speedy. The front-firing speakers... this is one area where I wish that they followed what Apple did with the iPad Pro, and put 4 speakers on the front, instead of 2. In portrait, the audio loses stereo effect. Not a problem when in landscape, where they will be used the most for fullscreen video, and with the keyboard attached, but in portrait as a tablet if you are listening to audio without headphones, it's an issue. Other than that the speakers sound quite good for a tablet. Turned the volume all the way up on the AC/DC S4 intro video, and there wasn't any bad distortion, but this was inside of the cavern of Best Buy, so hard to tell. After playing with it for an hour the back of the surface (m3) was warm to the touch, but not hot. Don't really have a baseline to compare it to. I'm more interested in the i5 version, I wish they had one to try. I left feeling that this will be a very popular device. They absolutely nailed the input devices. Everything looks and feels much more polished. It doesn't seem like the new keyboard and trackpad should make that much of a difference over the S3... but it does. Luckily S3 owners can upgrade to the S4 one. I felt like I should get as much RAM and SSD drive as I can afford. The CPU---well let's wait and see the benchmarks. I saw no stuttering with it though. I think I am headed towards the i5 as this seems like the mass-market CPU for the Surface and where it will see the best all-around combination of performance, battery, and cooling. Think I will probably stretch to get 16GB RAM and 512 SSD though. The SSD in the S4 is very fast. Coming from a late-2008 original unibody Macbook with a Core 2 Duo and 4GB RAM... this will be a monumental upgrade for me. I usually don't keep notebooks this long... but I prefer only to upgrade when revolutionary changes in the industry are obvious. Apple provided only incremental planned-obsolescence style upgrade path for the Macbooks over the past 7 years... I wanted to buy another Macbook for several years now... but they didn't ever give me a reason to. Now its clear Microsoft is taking the torch with the Surface. As for apps--I wish people would compare the Windows app store to the *Mac* app store. Apple's app store for the Mac is a *joke* and they seem to all but have abandoned it. With the new Surface devices the W10 apps will come flying fast and furious now. Heck I might even write one myself. It's fertile ground compared to the overpopulated Apple and Google mobile app stores. Oh... the BestBuy workers said that they are supposed to be getting SurfaceBook demo units on the 18th.