nah, a couple of my friends had the m3, didn't like it and a couple of the games didn't work with it besides, it's the closest thing to the r4, and the r4 doesn't work... and if i'm not mistaken you need to patch the games (or create the saves with a pc)
m3 is exactly the same as r4. the difference is on the main menu, it would say m3 rather than r4. and the firmware release is also different. there was a thread about this before, and they are EXACTLY the same in terms of how it works. yes you would have to patch if some games dont work, but usually the new firmware fixes it. but m3 simply is not the only one that needs patching, r4 does also. http://forums.afterdawn.com/thread_view.cfm/585468