The part of the range that your sub is handling seems to be pretty smooth -- at least much smoother than the range the 80s are handling. I would try setting your crossover to 80Hz and run the same test again to see if the response improves. If it does, at least you'll have less tweaking to do.
As for the upper bass range, I would try altering the positioning of the M80s. First thing I'd try is decreasing the toe-in angle. Instead of pointing the speakers right at the middle of the couch, point them straight ahead. (This is just for testing to see if it will make a significant difference.
Once you've got the system sounding its best without room treatments, then it's time to add bass traps and first reflection absorbers.
EDIT: Oh, and nice room! I'm jealous of the setup, but especially the ping pong table.