I bought two Surface Books. Same model - i5/8Gb/128Gb, same retailer, same price. They were delivered in identical boxes on the same day. When I powered on the first Book, it froze within a few minutes, requiring a reboot. After that, it froze frequently - every few minutes, requiring in each case holding down the power button and then rebooting. After struggling through some basic setup operations, but not even getting to the point where I could sign in to my MS account or run Windows Update, the settings menu would no longer appear. Every time I clicked on settings, I would see the outline of the settings dialog box, but it would disappear immediately. The same thing happened no matter how I tried to access settings. As a result, I could not change any further settings or install any updates. Unable to get the settings box back (rebooting, going into BIOS, etc.), I tried to recover windows. At that point, the Book became stuck at Resetting Windows 1% and did not move for 12 hours. Powering off and rebooting resulted in an endless loop of the word "Surface" appearing and disappearing every few seconds, with no other activity. That Book went back in the box and back to the store. Dead. Good riddance. When I powered on the second Book, it worked perfectly. I signed on to my MS account, ran Windows Update several times, changed all the settings I wanted, set up my ARC mouse, installed MS Office, detached and reattached the screen multiple times, etc., etc. No freezes. No lockups. No problems at all. The second Book performs exactly as I expected it to - which is, frankly, awesome. I am loving my second Surface Book, and it is everything I expected it to be (and everything the reviewers said it was). I guess the moral of the story is that whether you get a good one or a bad one is the luck of the draw. Best of luck to all!