Honestly I expect Sony will still win the holiday's and I''d be surprised if they don't. They have a lot of momentum going into the holiday season and I'd say their marketing has been a lot stronger than Microsoft's.
Honestly speaking I've used both a lot, and as far as features go I like the Xbox One's UI more, but I prefer Sony's for fluidity. Using the Xbox One's UI lately, everything just feels like it loads way too slowly and it's pretty off-putting. I also think having to do things like Snapping to invite friends or send messages in-game is just too much of a hassle because it loads too slowly.
That being said Sony needs to do a lot of work with the PS4's messaging and trophy syncing. Messaging is a complete mess in the sense it either takes forever to load, or it just doesn't work at all and the same goes for trophy syncing.