Had 2-3 hours on mine last night. Initial impressions:
Generally, I'm really impressed with the console - from build quality, to the pad design, to the user interface. I think it'll take a while to work out exactly how to use everything! I've got my Sky going into it for example, but I don't know why as I think that means the Xbox will have to be on at all times for me to get into Sky? I dunno, maybe I'll change this.
Onto games, Dead Rising 3 - I'll echo the previous comments, it's just carnage! Very enjoyable.
FIFA14 - Massive surprise at how good this looks and plays, what an upgrade over the previous gen.
I'm yet to play COD Ghosts yet, but I'll probably have a blast online at some point today. I'm already thinking about what games to buy next. Impressed by the £44.99 price tag of Ryse and Forza on the Store.