I dunno about the "more powerful system" part. I only run TR on Medium (Normal) with some things on High, in 1080p, and I get an average of 40-45-ish PFS (in less crowded areas, 60 FPS) with occasional dips in more intensive areas. If I set everything to High I get a noticeable drop in the framerate. Of course, "being able to run it" means a different thing for each user. For me, 50-60 FPS would be optimal, while others praise the heavens if they get 35. So yeah.
Also, most people with the same video card that I have (GTX650, non-Ti version) often say things like "oh I can run this and this maxed out", but none of that matters when no one mentions the resolution they're playing on. For all I know he could be playing on an old CRT at 1024x768. And I'll be honest, I like my stuff in 1920x1080. 1600x900 is the absolute lowest I can tolerate, but even that bothers my eyes. This isn't really being a graphics whore IMO, but rather my eyes being sensitive to image quality on a game being too blurry.
Lesson learned: next time I won't be a penny pincher when shopping for a GPU.
