The only thing in favour of the One at the moment is they have shifted all new game manufacture to that console.
Obviously the x-box One has all the multi-media bumf, but if all you use it for is gaming the graphics and gameplay are almost the same between the two. One runs at 1080hp while 360 is almost all 720p, but you'll only notice the difference on a really big Telly (I'm relegated to the 28" TV in the spare room for gaming, trust me, it makes no difference).
If there is a new 'must have' game out for the One, then you'll have to upgrade to play it.
I've put it off simply because there is a massive back-catalogue of games for the 360 which I've never even touched and they can be had for peanuts at the moment.
When Fallout 4 gets a release date I'm selling a watch and heading straight into Game!