Like TALO said, avoid GNC. Or any other "trendy" stores like that. All they are is the same product you can get elsewhere with a "trendy" logo on it for an all too expensive "trendy" price. Especially when it comes to CM. (simply my opinion here, sorry if anyone likes those places)

Also, be careful to check your ingredient listings on the monohydrates. LOTS of companies like to throw in a ton of refined sugars (Cell Tech comes to mind right away, having something like 75g of sugar/serving). There's plenty of cheap mono powders out there that aren't going to add all the extra crap in there.

I personally haven't tried the CEE, but it's pretty well unanimous among my friends that have, that it's much better in terms of no bloating and no loading and all that jazz.