I'am using Gamemaker 8.0/ 8.1 and the new HTML edition. Using C2 since a short period. C2 is much more stable but the possibillty of GM of using inherritance is very power full. C2 is faster and much more stable. So i�m using C2 more and more. This is a fantastic enginen en much cheaper.
I will use GM HTML for sure, because of his great flexibillity and C2 for sure for the perfect functionality. regards.