Overall, I'm happy. If I had a do-over, I would probably hold off on the PS4 for 18 months until it has more awesome exclusives and instead put my money towards a Steambox in the summer if it turns out to be awesome.
Xbox One -
Positives: Lots of potential with the interface, good launch exclusives, and lots of future exclusives to look forward too. Live is great as always. UI is snappier than before. Controller is solid overall, though it may be a step down from the 360.
Negatives: Kinect isn't worth it IMO, the inability to get launch games up to 1080p is quite embarrassing, the UI can feel clunky and cluttered.
PS4 -
Positives: Awesome new controller, extremely quick and smooth UI, several free games at launch, seems to be the better platform for most 3rd party games.
Negatives: Controller battery life and most importantly LACK OF AWESOME EXCLUSIVES for 12 months.
Overall, I think the PS4 is the better physical console, but the Xbox One will have better services and exclusives at least through 2014. So in an ideal situation I would have the PS4 as my console with the Xbox One's exclusives and Xbox Live service on it. Unfortunately, that won't happen.