My god...it worked smooth on my system and I don't even have a dx10 card. Played with medium setting (over 35fps). I think it's going to be better optimized than Lost Planet..
My specs are in my sig and @ 1280x1024 on medium settings I was getting as high as 30fps and as low as 10fps and if you call this smooth I'm sorry its hardly that.
Smooth is a constant framerate of 30fps or higher and never dipping.
I also felt the little that I played I was playing a overglorified Far Cry game with a fancy suit and the enemies are damn near impossible to kill. I can unload 8 bullets from my clip into them and they hardly flinch!