In of itself I have no truck with this, as nVidia shows, it can be done well. However the proprietary drivers for ATI/AMD graphics products has always been a hateful, spiteful experience. One which, if you're exceedingly lucky, you might get working, but more often than not will leave you frustrated and cursing the Canuks who created them.
To have something that works out of the box, won't break every time you update the kernel is a wonderful thing 
nVidia proprietary drivers are a bliss indeed. apt-get install nvidia-glx nvidia-kernel-dkms and be done with it. Updates nicely even with custom-built kernels (assuming you use make-kpkg). I don't know what AMD are trying to do but they're doing it wrong.
