Well, MS finally suckered me in with the MCC announcement and accompanying vids. So, I picked one up (w/ Kinnect, Forza 5, and a 1-yr Live code) last week.
I have to say it's a mixed bag, but overall, I'm happy with my purchase. The XO is now the main consumer electronics device of my living room, although I still have to use my Intel NUC for streaming vids/music. The TV integration works very well and my live-in girlfriend likes it a lot, even though modern-day gaming is a foreign concept to her... The fact that I can play Forza 5 or Powerstar golf and snap whatever TV show or movie she is watching at the time, or even Netflix, is a feature I never thought I would value so much.
The voice commands make me feel like I finally have the living room of the future that I always imagined as a child. However, it's not as accurate as it should be, currently, for consumer release. I can also see the novelty of voice commands wearing out soon enough, unfortunately.
The dashboard does give me that sense of "Live" and community connection in a way, which is something I always liked about the 360. I also like that the Marketplace is integrated with Twitch.tv and seems more intuitive than other "app stores".
I also really, really like the gamepad (dem triggers!). I didn't think I would after reading a couple of "opinion" pieces about it. But, I should know better than put any kind of stock into other people's rants/reviews....especially something as subjective as how a piece of plastic feels in your hands.
That being said, if the Xbox One wasn't as feature-rich and had to rely solely on games and game performance for its reputation, I don't think the Halo franchise would be enough for me to have jumped in. The thing is, I have really been enjoying the games so far and usually gravitate to the XO when I'm in the mood to play something. This may be mostly due to the fact that I've only had it for a week, I have 3 new games that are fresh to me, and consider the gamepad to be my favorite of this gen.
TL;DR:
Halo franchise and TV/Netflix snapping abilities.