Okay, now that I've had a chance to play with it a little and while it's currently downloading resogun, Contrast and Warframe, I'll share some impressions.
Placement in cabinet - it's taken over the spot where my 360 was. A sign of things to come perhaps? For reference, my X1 is in the spot my PS3 was...
Controller - goddamn, this is a significant step up from the DS3. Nice snappy triggers and the sticks are pretty tight too, compared to the looser sticks and mushier triggers on the X1 controller. The lightbar is pretty damn bright, so much brighter than I expected, thank goodness I had some black tape to hand....
The UI - fantastic. It's simple and straight to the point. Nothing is hidden in various sub menus, everything is intuitive and doesn't require searching out an answer on the internet or becoming frustrated because you can't find anything.
The console - pretty damn slick and damn sexy too.
Overall, it's incredible so far. UI is straight to the point and doesn't rely on any gimmicks, the controller is a huge step up from the DS3 and dare I say it, rivals the 360 controller in terms of comfort and it's whisper quiet too so far.
Now the games, I probably won't have time to start Knack or NBA 2K14 tonight as I have a lot of work to do, but I'm hoping to get at least one session of Resogun in.