I am using M2i's for surrounds, with M80's & VP150. I'm happy with the tonal balance. I've heard on this board that the bookshelf speakers are the way to go if one is more concerned with mutichannel music, than moves. The QS series is the way to go for movies. Plus the M2i's are quite a bit cheaper than the QS's. I haven't heard the QS4's or 8's, so I can't compare, but the M2i's do the job very well I think.