The Dell XPS 12 Ultrabook has a number of problems that require too much attention. Perhaps that's why I bought one new today for over $400 off list price. This Ultrabook has a 12.5" 1920x1080 screen, touch screen, Intel Core i5, 4 gigs of memory, 128 GB SSD, and has a nifty screen flipping feature so you can use it like a tablet.
Here are a few problems so far.
The keyboard is bad and the keys stick up unevenly. Normally this isn't a problem but the white LED backlighting points out to you which keys are jutting out. It's okay to type on but I prefer to flip it into tablet mode and plugging in a tenkeyless mechanical keyboard.
More importantly, the touch screen can stop working. What happens is the two I2C HID Devices under Human Interface Devices are disabled by Windows because it "detected a problem." This happens randomly but most often when coming back from sleep. I got used to the touch screen, especially in tablet mode, so I'm not sure I want this feature disabled. Simply doing 'Scan for hardware changes" in the "Action" window will re-enable them but they will eventually stop working again. So updating the BIOS should fix this. The BIOS update from Dell from A03 to A04 updates the BIOS, another Intel firmware (likely the touchpad's firmware since it's an Intel device), and a third firmware, and reboots. Following this, updating the touchpad drivers from Dell should do the trick and I will be watching this for success.
Finally, updating to Windows 8.1 complains that my user is not an Administrator. Well, this is, of course, incorrect. What I did to fix this is to remove the Windows Update 2871389 from the system, reboot (takes a long time), run Windows Update and install updates again, reboot (again takes a long time), and then go back to the App Store to download it again. Finally, now I'm waiting for over three gigabytes to download.
The screen is beautiful and it's too bad Dell and Intel didn't test this Ultrabook enough. They must have lost a ton of money on this model. My local store had around 25 new in stock at fire-sale clearance prices. You can't get a 12.5" 1920x1080 Ultrabook at anything near this price, let alone a Core i5 with 4 gigabytes of memory, 128 GB SSD, and a "carbon fiber" case, whatever that means. Just make sure you have the patience and problem-solving skills to work out the problems.
Windows Experience Index details (before Windows 8.1):
Memory 5.9 (bummer)
Graphics 5.7 (Flunky Intel graphics)
Gaming Graphics 6.5 (Flunky Intel graphics)
Disk 8.1 (Superb!!).
A great value for a new Ultrabook over $400 off the list price. Too bad for Dell's profits on this troublesome Ultrabook.