I own the a case with basically the same structure as the GS (different bezel, fan setup and side panels) and it's great and very pleasant to build in. Can't speak for the CM but the sentey case is solid.
Thank you both. I was actually just looking at that BigTroll (I already have the HAF 922 Full)...can't believe it is just $.1 from free shipping! XD
Now I'm trying to decide between it and the Zalman Z11+