Got home with my console around 1.10am.
Setting it up went as smooth as you like, as did bringing over my gamertag etc.
The day one update was smaller than expected (varying reports said 1.2gb - 2.0gb but it was only 500mb) but it took about half an hour - I guess the servers are taking a bit of a hammering.
My copy of Forza is physical disk. I also bought COD on disk, and I have Lego Marvel ordered - but that won't be available for about a week. All disks appear to have a mandatory installation to HDD. I think the installation for Forza was about 5gb but I wasn't paying attention tbh - was busy buggering about with customising profile etc. You can't play the game straight away, but when it was partly installed (about 35%? rough guess (a few minutes) - again I was preoccupied so never paid attention to the game installation) it flashed up a message saying it's okay to play now and the rest will install in the background.
Played the first three races, but it was about 3.30am by then and my back was aching from the little bit of crawling around behind the tv - and from carrying the console, which is heavier than expected - so I decided to call it a night. I ejected the Forza disk and put the COD disk in to start that installing to HDD so that I'm good to go on both games tonight. I then got messages telling me to put the Forza disk back in as it was still installing. D'oh! Ah well, I'll sort it all out tonight.
I think I'll get a wall mount (or shelf) for the kinect. I have it in front of the tv at present, and it works okay - but having it further back against the wall will allow it to see more of the room.
Also need to have a play about with the hdmi-in options. Will probably feed my Sky in, but might feed in the media player instead.
Controller's good, but will take a bit of getting used to. The thumbsticks are smaller than on the 360, but have a great feel and grip to them. The feedback in the triggers is great. The bumpers and face buttons are fractionally off where they used to be, but I'll get used to them in no time.
Voice control is a bit iffy on occasion, early impression. Not sure if it's my accent, the room setup, my being a bit quiet because the family were asleep, or just me getting used to asking the right things, but a couple of times it did the wrong thing and a few times it didn't seem to recognise my commands at all.
Of course I only had a fairly quick play with it all, and it'll be a different story in a few days' time.
I can confirm, though, that saying "xbox on" and watching the console turn on and go to your personal homescreen is pretty much the most awesome thing ever.