You could also try protovision
I got my MMC64 last week for the commodore 64. The drawbacks of using it is that it will only play single load games, multi loads will load but the second level won't because its trying to access the disc drive. I've found quite a few single load games won't load but if they've been backed up by something like the action replay they will load. Its fast loading and you can read your old discs back to .adf format and also write .adf format back to disc.
Theirs a bios upgrade that I found is meant to load some of the IDE64 fixed multi loading games, but I couldn't get off the menu. Also this bios will not reflash the MMC64 to put the 1.1 bios on. Some advice when you get it, download the recovery disk and write it to a disc incase you need it, this will rewrite the bios back to the MMC64 if anything goes wrong.