Ossie, I too found a lot to enjoy in MMX. I played through every combination available, and even got into the DLC's (but never finished those.) There's been so much bad press about X, that I thought I must be a real rebel to have enjoyed it.
Admittedly, there were some bad glitches (but not insurmountable.) If you played too long at a sitting, the game was likely to crash. But if you only played for about 30 to 40 minutes, it worked fine. Some of the posers in the game were too tough for me to suss out, but there are/were a lot of hints online. (I've written down a lot of them, so if you're stuck, I may be able to help. Just be aware that I can't go back and play the game, since I'm boycotting UBI at the moment.)
As a former professional map draftsman, I never could wrap my head around MM9's inside-out, mirror-image setting. I tried to map it, but failed miserably. So that's the only M&M I never finished, along with MM7 Dark (but I could do Light.)