I also think that the 6100 would outperform the GMA, especially in 3D games/apps. I had the GMA900 in my previous laptop, and it could barely run CS 1.6, so I dont think the 6100 woluld be worse then that.
from all of the stuff ive seen through my line of work i can say honestly that the GMA 900 is a real poor excuse for a "graphics chip". the 6100 is the way to go even if it a little long in the tooth.