Marc,
At present i have the M60s, set about 6 feet apart and we sit about 8-9' away on the couch. This is the ABSOLUTE minimum distance setup i would recommend to anyone. I have found that when i can actually get the speakers further apart, the soundstage was alot less finicky for placement. Sitting that close to the M60s also presents a bit of a 'in your face' sound when the volume is turned higher.
If you can get the M60s beyond the 6' distance, you should be good for sitting anywhere from 8-14' away.
You cannot go wrong with the QSx series of speakers, especially in odd rooms.
