5850 overclocked, performance was fine, yes a few slower moments throughout but few and far between not nearly enough to hurt the game.
Disable tesselation and DOF(sucky effect anyway) and performance will pretty much double with zero IQ difference, or not noticeable. Overused effect in terms of code, with little actual quality increase, screams to me that its been implemented in a way that simply add's a performance hit without an IQ increase, just like AA in Batman, where ATi cards were doing all the work, but it simply wasn't rendering the final AA, performance without use.
Its called Nvidia bought game that add's something to make AMD cards suck on purpose, shocking? not even remotely surprising, its a "launch" title for Fermi, I would have been surprised if it wasn't programmed perfectly to take advantage of Fermi while purposefully being coded in a way to cripple 5xxx series performance. THe fact that you can disable both without a IQ decrease and a MASSIVE performance jump says it all.
A 5870 doubling 4890 performance and a 5770 beating out a 4890 shows that the new gen really is much better than the last gen, just took a while for games to be tough enough to show it.
Unfortunately I found the game dull as poo, story is, well, daft as heck, accents nice, dialogue poo, laughable long and boring bits interspersed throughout, lots of entirely boring on the rails sections. A few very nice fights to be fair, but too few and far between. Monsters, like with several other stupid games like Crysis, Bioshock and a bunch of others, have no variety and similar start to finish. Crappy gun upgrades, wanting to be RPG ish like someone said above, but with a truly stupid money/upgrade system that makes it a needless add on.
Its ok, but linear and basic with nothing particularly new, a few good fights with lots of awful ones and a story that doesn't make it stand out from the crowd. The fact that it was made by a large portion of the Stalker team(from what I understand) is not even slightly surprising, all the same faults, the same dodgey type of story, same feel, same overuse of new effects, same horrible performance drop for little IQ gain in a few settings and same wanna be RGP/fps mix, failing miserably.
ITs worth a play through but I'd recommend waiting for it to be MUCH cheaper as I wasted money on another game only worth 1/3rd of what I paid.