I've used the Bose PAS since it first came out. It's an amazing feat of engineering. It functions as my PA system, and I use it in conjunction with a small M-Audio FastTrack. Instrumental accompaniment comes from my computer and goes through the FastTrak to the PAS. My theremin goes directly to the PAS. Once I have the two sounds perfectly balanced, it truly sounds like a I have live band playing with me.
The system IS very expensive. It's price has remained steady at $1,995.00 for the power stand, speaker towers and the subwoofer. For most people I'd say it's unnecessary -- there are plenty of more cost effective ways to get good sound. However, if you really do a lot of traveling around, playing in venues ranging from small clubs, rooms in museums, to huge concert halls, the PAS is well worth the investment. It virtually guarantees that you will sound great and you'll never have to get stuck using someone else's shoddy sound system. That has happened a number of times -- I get to a place and the set-up is either very weak OR it's configured in a way that makes playing really risky -- for instance, many places have nice sound set-ups but they're all geared to what most musicians require, a PA that faces out to the audience with some sort with a monitor system FACING the musician. If you've ever tried to play a theremin with the sound coming directly AT you from one source and the sound moving AWAY from you from a PA (what the audinece hears) that's IN FRONT of you, you'll know what I mean. It's very disconcerting and takes a lot of getting used to. I've never worked anywhere where the people in charge knew that, for a theremin player, it's best that sound come from BEHIND the player. BOSE, however, engineered the PAS to do exactly that, regardless of what instrument you play.