Let's put it this way - If Titanfall launched on both XB1 and 360 on the same day, and was priced at $60/$30, respectively, I would still buy the XB1 version.
However, I wouldn't buy an XB1 just for one game. If there are other games that interest you other than Titanfall, the choice is simple.
I just don't understand how people could defend how ugly the game is on 360. Not only do we see a big resolution difference, but also lower quality textures, a washed out color palette, missing or completely changed lighting, a frame rate that fluctuates anywhere between 30-50 (it's still worse than XB1 since it stays in the lower range more often) that can dip even lower, a reduction in particles/explosions, reduced grunts/AI soldiers in LTS mode, and the worst screen tearing I've ever seen. Having to lock the frame rate at 30hz (lol) just to reduce the horrific tearing, but not fully eliminating it, is not the way Titanfall should be played, and definitely not on par with the XB1 version. Stop being crazy, people.