Mesa vs propietary

Is it normal that the free Mesa driver is alot faster than the ATI propietary driver?, at least for desktop usage.
That is, using both latest drivers, 9.11 and 7.7

only drawback is no 3d acceleration. (HD2600XT)

I think I remember reading somewhere that the open source stack has faster 2D performance. So I’m not totally surprised by that.

Its a huge difference IMO. Konqueror and similars launch at least 2x as fast