ATI Radeon HD2900XT is quite competant with NVidia GeForce 8800 GTS, while the NVidia is still faster in normal and AA scenes, the ATI beats it in HDR shader language scenes. The interesting thing is that it happens in both OpenGL and DirectX9 games, like Doom3 (OpenGL), FarCry (DirectX). So I wouldn't say ATI is bad at OpenGL, ATI seems to be now better than NVidia at modern shader language graphics.