Personally, if the primary goal is 'simple rules', I'd rather something like FATE than a lobotomized version of M&M (2E had 6 stats, I'm not certain why 3E felt the need to add 2 more). M&M and the whole D20 metasystem's attraction is the endless ways you can tinker with skills, feats, and other junk to perfectly customize your character's idiosyncracies. Simplicity of rules and gameplay is probably better done by systems designed to be simple from the ground up.