Yeah, I have desktop effects:

[kwhiskerz]

I hope someone in the know answers your question. I would like to add some, on 
topic:

Having chosen OpenGL, should one choose:

1. Texture from Pixmap, Shared Memory or Fallback?
2. Nearest, Bilinear or Trilinear?
3. Direct Rendering?
4. VSync?

So, as to my experiences regarding your question...

I use Intel graphics. In Fedora 9 alpha, it was not possible to use OpenGL, 
only XRender, which supports less effects and is slower, I thought. Since 
Fedora 9 beta and the actual Fedora 9 release, it is possible to use OpenGL, 
which I now use without any apparent problem. I have set options: Texture 
from Pixmap, Bilinear, Direct Rendering and VSync, but haven't a clue which 
are best, but I assumed that turning them all on would give me the fullest 
user experience. It would be nice to know which is the best choice. I am very 
pleased with the effects and performance.