Which cree conversion, there are a number available at the moment? Although they are similar, it would seem they are not identical. People have reported issues with the Litemania version and the G2, but the DX version appears to work. You might want to be more specific.
I don't own a G2, just a couple of 6P's with the DX $12.50 drop-in.
I do have an airline buddy who gets home tomorrow and he has a G2.
I'll get his G2 and see how my DX $12.50 drop-in fits and report back later....
I have the LiteMania module in a G2. Somebody did some work to the reflector to make it fit well, and it uses an aluminum foil strip for contact. It works just fine and fits fine now, but is just a bit cheesy. Still use it and like it though.