ok, for someone playing on max settings at 1280x1024, you do realise its almost 50% more pixels at 1680x1050, most people playing "high" settings would be playing with a higher resolution. what exact settings did you use?
anyway, i get, somewhere between 40-70fps at a guess utterly maxed out (tell a lie, AA only 1/2lvl up but no idea what actual aa setting that would be and if nvidia is doing good/bad/fast aa there). but every bar maxed, full dynamic lighting. thats at 1680x1050 with a cd2 @ 3.5Ghz and a 8800gtx on vista64. although thats utterly unstable, i said "I", opps, i clearly meant my m8 just told me that ¬_¬
however, it might be that vista 64 doesn't like the dynamic lighting or something because turn that off and it goes from completely unstable to not a single issue with graphics............... notice i said issues with graphics
its still kinda crap so far, i got a couple rifles and they, suck, i ..opps, my m8 tried to kill a guy 10 metres away, who was unsuspecting, i unloading a automatic rifle into him with standard ammo and i dunno, i got hit several times and it musta taken 4/5 bursts probo 2-3 shots in each to take him down. its ridiculous.
while i can load up ammo in the shotty for range and less damage, or less range and high damage, i can sometimes pump 4 shots into a mutant pig thing 10 metres away and not kill them, or use standard pistol ammo and kill them at 30 yards with two shots. makes utterly no sense.
the graphics issues with heavy equipment needed, its just like having an x800 on hl2 with hdr, without it game runs great, with it, it doesn't so much. the dymanic lighting, with it turned off i was running like 130-160fps, its an overly used, quite pretty at times but way way to overused graphical effect. without it i would imagine a lower end system would easily play it even with other thigns at higher detail levels.
now maybe you do die way to easily in the game, or maybe you just need to get used to constantly bandaging/medkit using in battle which you don't really do in many fps games. but so far i would say you die far too easily with enemy's and beats being too accurate while you can't kill them that easily. but this is why the AI's lame, they often i guess semi realistically spread out and walk around, but the part where the AI is lame is. if you use shotty with high damage low range stuff, you can simply run at the nearest guy you can get stupidly close before they'll even start to fire and only the nearest guy will, you can blow them away in two shots, then run/reload to the next guy. the groups seem to be utterly retarded.
