Also for consideration:
I’ve found that I am able to be sorer (more sore?) with greater stress/tension (both emotional and physical).
For instance, I am more sore in a muscle group with which I am able to exert greater stress or create greater tension within. This isn’t just a MMC thing – sometimes it’s just the nature of the lift you’re able to perform (i.e. squatting 315 will inevitably create more stress in the muscle than performing a single leg extension with 50 lbs).
However, it also applies to emotional stress.
For instance, I can tell a difference with how sore I become the next day if I had a really stressful day at the office before I trained. For a more extreme example, I was once involved in a car accident on the freeway where the car behind me flipped over and the cops were questioning me as to fault (the guy in front of me slammed on his breaks causing me to do the same, and the guy behind me swerved to miss me, over-corrected and flipped his vehicle). Anyway, I was late to the gym, but hit legs anyway. To this day, that is the most sore my legs have ever been.
I would guess this has something to do with cortisol levels pre-, intra-, and post-training.
All meaning: There could be a large number of things relating to why you don’t get ridiculous DOMS in some places while you do in others. = )