Don't have the game myself, but I'm considering it and I have a 680 so this information is troubling. Have you tried running it in Borderless Windowed mode? A lot of people are saying that smooths out framerates; seems to be the only way to enable triple buffering.
I'm running the game on High textures now, with my GTX 670.
I would assume that a 680 would be able to run it slightly better than me (my rig is in my signature), and my CPU isn't exactly "high-end" anymore as well. I was running the textures on Medium for the first two days, but I switched to High for a test last night and to my surprise it still runs smooth enough, I did notice a performance impact but it wasn't bad enough to justify going back to Medium. At those settings it's probably running within the 45 FPS range or so (happy with that). I'll probably check my actual FPS with Fraps later today (for now I'm only guessing, but it's smooth enough to enjoy the game-play).
I only turned off both Ambient Occlusion and Motion Blur, the rest of the options are at their respective highest values (well, except for the textures of course, at High, not Ultra). Note, however, that I run it at 70% resolution (1432 x 1074) so that certainly helps. I ran the game at 80% resolution instead but with the textures on Medium, and even though the resolution was a little higher the quality of the textures wasn't satisfying enough (doesn't mean that Medium is bad though, it's actually pretty good compared to other games' "Medium" settings). So I opted for higher quality textures and slightly lower screen resolution instead, and I prefer that result so far.
With a GTX 680 I'm pretty sure that running at 80% resolution with High textures shouldn't be a problem (and would run smooth enough). There's no denying that the game's "recommended" specs were not joking around though, but I'm genuinely happy to see a current-gen game actually using "modern" hardware well enough, it encourages me to think about a full PC upgrade sooner, rather than later.