Ok pixel shader 3 is not used by alot of games. The only reason people diss ATI is because of its poor performance in Doom 3. The x800 xl is in the area of the 6800GT in other areas besides Doom 3. However, that is a major game, and ATI has def lost many sales because of this aspect.
Ya, and make sure the pentium has hyperthreading. It will play Bf2 just fine, as the x850 is designed to compete with the 6800Ultra.
Also, if you plan on using max settings and max resolution on bf2, I would suggest 1.5 Gigs of ram.