After a quick discussion with maniacal bookshelf buyer Robb, who has absolutely guaranteed that there is no viable way anyone on this planet could possibly hear even a remote difference between the M2 and M22 (to the point where he'd buy me a new Ferrari and paint my house if I could), I decided to go with a pair of M2s. They'll be coupled with the PDR10 fed by a cheap (open box) Yamaha HTR6030 (for when I convince myself to buy surrounds in a couple of weeks).
Now I'll have to wait and see whether I'll need to reconfigure the room (M2s are only marginally smaller than the M3) or get away with leaving them on the desk! New speakers are really the only impetus for getting me to clean out a room, so maybe I should have gone with the 22s after all.
