TR is a much bigger brand (i.e. non-gamers know it too), but Fallout is bigger in the gaming community, which let's face it, is far more important to sales.
I think it'll do OK. In many ways, the two games cannot be more different.
I really wanted to like Fallout 3, but grew quickly bored of it. New Vegas was even worse. I simply don't have the staying power to go longer than 30 hours with one game. 40 hours is my maximum. Coupled that with the fact that I'm terrible at forgetting controls really quickly if I take a break of longer than a day or so. So I either get bored or I get quite good at a game, have to take a break from it for a bit due to work etc., get terrible at it again, try to start from where I left off and can't progress, so pack the bugger in. Give me 12-20 hours and I'm happy.
I loved TR 2013 and enjoyed the fact I could smash it over a weekend. I just don't have the time to commit to a long-haul with a game,
Buy it on Friday, re-sell it on Monday.