Many, many others seem to have had decent results with it. Keep in mind that many laptop and motherboard vendors do screwy things with the chips they implement- some of which would cause problems. I know for a fact that the driver works FINE on my eeePC, but the same GMA on my Dell Optiplex 745 at work is unstable with 3D operation and I had to swap in a 6200LE just to work with things on the machine. BIOS settings and timings can play a BIG part in things working or not.
I quote your comments here:
I'm not saying this only occurs on Linux either. The very same X3100 chip would blue screen windows, until the July drivers fixed what looked like an invalid memory allocation (this certainly didn't help my opinion of this card).
As for performance... My GMA950 on my eeePC works well as does my X3500 on my HTPC. The Dell Optiplex 745 GMA950 DOES NOT work stably and when it does run, doesn't do 3D as well as it ought to. I strongly suspect you've got a problem with your laptop that puts the GMA in a suboptimal configuration.