I live in an apartment, so of course it may change in the future. I have a relatively large living room (but probably relatively small by house standards..) My front speakers can be 6 ft apart and somewhat away from the wall. The situation for the rears is worse. The couch is all the way to the back wall. Things are clear on one side of the couch for a speaker, but on the other side it sits in the corner formed with the back wall by the back of the (non-removable) wood bookcase, and the couch can't be moved away from that corner more than just to squeeze the speaker in. I imagine this is pretty horrible for a speaker placement. I am getting close to deciding on B&W CM4s for the front, but really don't know what to do for the rears - the matched, same-line CM2s are $900, while lower-line 601s are half that. I wonder if it would be a waste to get CM2s for rears especially with my current placement - or should I really look forward, to DTS music perhaps, lots of movies, future different living place, etc. - and get a matching speaker set? I guess what I'm asking is, does the difference between CM2s and 601s - for rears - or, in general, ANY different-series, step down speakers from the fronts - would warrant extra $500 in the ~$2500 system? How important is the issue of matching... Thanks.