60fps would be nice, but a smoth 30 fps is good enough for these games as Uncharted 1-3 showed and if they are already hitting well beyong 30 fps in this that hopefully means it is 100% sustainable throughout the game, although the stage might not have been the most demanding on the hardware.
For perfect 60fps they need to be at ~70fps throughout all of the game aswell, so pretty much double than what they are doing now - might be impossible to achieve with the current quality.







