I’ve had a few ATI cards over the years and have occasionally found software doesn’t like them so I’m sticking to Nvidia for the moment. Except in my laptop where I’m stuck until I replace it.
Some examples of ATI weirdness:
I found some weird problems with Photoshop some years ago where some layer blend modes would show solid vertical lines at certain transparencies. Very, very annoying and I don’t know if that was the graphics card or photoshop itself. Doesn’t seem to happen on the laptop though.
I found Maya didn’t like the ATI card for certain things. The paint icon would just leave crap all over the screen, marking menus wouldn’t appear and sometimes certain viewports would display nothing (perspective and top would be fine, but front and side wouldn’t show). Those sorts of things. And no I checked the clip planes and they were fine.
Silo doesn’t react well with the brush circle on my laptop. It smears the view when you hit the sides of the viewport.
It seems there’s something wrong with the overlays used for things like icons.
Max seems fairly happy with whatever card I’ve had. I don’t need shaders much but when I’ve tried things out (mostly messing with Ben and Kees ShaderFX) it doesn’t seem to have had many problems.
These problems were mostly with the Radeon 9600 or the laptop variation (Radeon mobility M10), I haven’t tried the recent cards which I hear are better.