I'm no audiophile expert but from what I understand, it is 'ideal' to have identical speakers/drivers for the 3 front channels.--and I'm not saying that it is not possible to have correctly timbre matched system otherwise--but, if this is the case, would it be feasable to use, let's say for example, in a epic 80 system, an MT80 for the center channel(vertical placement)--placement issues aside, wouldn't this be the best setup-or are there other issues to consider here.

i think the other issue would be your neighbors banging on your door or posting an eviction notice on the door. just imagine 3 80's cranked, in the summer with windows open...oh my what a pleasant thought.
dan

kcalvano,

Yes, if you can nicely place an M80 as a vertical center channel, that will be the best L/C/R configuration (for example, if you are using front projection, this is quite feasible ).

Dan, don't know about the Canadian tuntra, but in Texas, we tend to close all windows in the summer.

Using matching speakers for all 5 is also sometimes used. For those who can afford it! however, unless you were using it for 5.1 music, i would not bother (unless i had the money)

Yeah, and the QS surrounds often do a better job of simulating those multiple surround speakers in the cinema theater (at least for movie soundtracks and music videos).