Don't forget that the most recent Dolby Pro-Logic IIx will also matrix in a rear surround effect in stereo while watching V, listening to 5.1 encoded DVDs or CDs and can produce 7 channels of listening pleasure for your music sources.
Note, however, that while the rear speakers will be "on," there is no guarantee about what ifnormation gets sent to them to play. For example, you may enjoy the idea of having a 5.1 channel DVD play in 7.1 for the added rear field ambiance, but may find that the matrixing technology ni place actually reduced localized side surroudn fields, or lessens the impact of an otherwise very well mixed 5.1 CD....
I went with a 7.1 set-up, including the RX-v750, which has DLPIIx, but have yet to get my Axioms, so can't comment on how much more "realism" the technology brings, or what it may do to interfere with the mix.
I also have a fairly small listening area, and will consider Alan's note in comparing the 5.1 to 7.1 in my system before jumping whole hog onto the band wagon.
