Hi, it works not worse than classic mesa on my RV620.I add --enable-gallium-r600 and modify package_ati-dri-git() in mesa-git PKGBUILD as it is already done for r300
(make -C ${srcdir}/build/src/gallium/targets/dri-r600 DESTDIR="${pkgdir}" install)
I test current (20101213) git snapshot. May be put it into testing and enable on next release?