I don't have my M-Blocks yet (scheduled to arrive tomorrow.) I'm using them for an HT system, adding 3 of them for external amplification for my front speakers. I do use the system for 2-channel stereo a fair bit, though, and am hoping this will improve things.

Not using them for a sub; my subs (SVS) are powered by their companion Samson S1000, and while the 200 is probably higher quality it doesn't have as much power.

Anyway, will report here on any wobbles or other problems. I'm going to have to dis-assemble my Flexy rack and move a few shelves around in order to make room.