How can you not have multichannel system

For me, two reasons:
1. It may be thrilling to feel like you're surrounded by other concert goers at a live event, and hear some extra reverb cues from the hall, but it adds little to that actual art that is occurring on the stage. As for older stereo recordings mixed to several new channels, to what end?? Unless it's a special sound effect like a pink floyd helicopter, what does it add to the performer/composer's original art to pretend that some of the musicians are behind or beside you (or that some manufactured resonances are added for feeling)?
2. In the name of high fidelity, that is the reasonably realistic repro of clean, dynamic transients, etc. at nice levels, the $X,000.0 that I have to spend on 2 channels of amplification and 2 speakers is going to be of much higher quality that 6X of each.

This goes for movies for me too, though they're not really my hobby like music. But unless it's Star Wars, or some other special effect type movie, I don't miss much with 2 channels.

...because the vast majority of music I like to listen to has not been released in surround, or even high-resolution digital (pick your flavor) for that matter. Of course I have surround for movies, but that's a different story. -jz

Music recorded for 5.1 or more by recording engineers who understand the media will sound best.
Rechanneled stereo will sound like colorized movies look.

If I can ever build a HT room, it will be for movie/sound in 5.1 or better. My current room would be a nightmare to convert, having 8 sides and a vaulted ceiling.

Like Eldartford, I experimented w/'4 channel' back when you had 'derived' and the various Matrix schemes....QS, SQ, which I suppose were just phase shift. I never bought any of this gear, but using by brothers stereo cob'd one together by wiring the back channel speakers in series from + to + on there own amp. When I listened to a proper LIVE album, you were right in the MIDDLE of the crowd.

I forgot to mention, and many people don't know, that there is a large body of "antiphonal" music...composed for two or more choirs or orchestras front and rear as well as side to side. Mono and stereo playback equipment is completely incapable of properly reproducing antiphonal music. Much well-known music is actually antiphonal, but is unknown today except in a "mixed-down" form. I have one SACD "J. S. Bach, The Four Great Toccatas and Fugues played by E Power Biggs on the Four Antiphonal Organs of the Cathedral of Freiburg" that clearly illustrates the benefits of multichannel. Once you hear this music played in antiphonal manner you will never again be satisfied with a stereo rendition.

Timrhu...Your question... "what listening perspective do you get with multi-channel playback?" Some DVDA discs let you select your perspective..."Stage" or "Audience".