ATI or Nvidia

Hi
I am building a new pc to run linux and I have been recommended an asus
board but it uses the ati cross fire gpu platform. I haven't really had
alot of success with ati cards but since they open up their device drivers
dwas wondering if they are better supported by the linux community. I'll
be running a dual linux system, fedora8 and gentoo. Eventually phasing out
fedora8 and making gentoo my linus os
.