I'm not incredibly skilled at Mega Man games either, but I managed to work through MM9 in a few days. It might actually be the only MM games I've beaten... made it deep into MM2 and MM3, but never FINISHED them.

That said, I'd say it's the easy-save system that makes it easier to go through. If I had to work through every boss every time, I might've had more trouble. Now, question is, with MM10 supposedly having an "easy" mode, how "OMGWTFIDEID" is it going to be on "normal?" o_O