Welp, I've had my XDM 10mm for about 5 months, and can't seem to find any issues with it other than it chucking brass into the next county (to be expected in a 10mm with hot loads). It seems to like everything I've put in it. Even ammo loaded to light 40 S&W levels (~950 FPS with a 175gr bullet).
I would and probably will buy another XD in the future.
It's a very pleasant gun to shoot. Accurate, and it handles recoil wonderfully. It gets a little snappy with full house loads (not bad), but moderate and light loads are pretty easy shooting. You could shoot them all day long. The only thing I've done to mind is put in a heavier recoil spring, just to help with the brass chucking issue. It'll probably keep the gun from beating itself up if I shoot a ton of hot loads too.
For $550, it's a pretty good deal. 10mm is so versatile that one gun could fit into several different roles.