Quick notes :
1) NoAA , but the good news it looks ok without it on 1600x1200.
2) Outdoor graphics are ok , the indoors levels however look much better with the use of unified lighting & soft shadows .. same goes for the high quality textures which usually are mixed with parallax mapping
3) The game seems to eat most of the video memroy! (at max settings) i get a heck load of stuttering on my 256MB X800XT which render it unplayable. it sutters less on a 512MB X1900 & once in a while with a 768MB 8800GTX. (& takes ~ 1GB of the main memory).
4) My frametate is ok (~ 35fps avarage) @1600x1200,16xAFHQ. not bad but i thought performance would be better than that.
5) Decent AI! STALKERs do flank , take cover & pretty resistant to your shooting. i'm playing in "Stalker" difficulty & still somewhat hard in general.
i once saw a fellow stalker taking weapon from another dead one!
.. it seems that they trade with better weapons.
they use flashlights in night times .. if you hide in bushes you usually become hard to spot until they are too close to you.
6) Radiation sucks. it can be pretty annoying at times as you need speical items to heal it. (vodka or medkits).
7) The game doesnt seem to take advantage from dual core CPUs
8) The dynamic weather system & day/night cycles are awesome!