Well, don't get too excited, Spiffy. From what I've learned, it all depends on what equipment you're running.
I was initially really excited about multichannel music as well, thanks to a few DVD-A purchases, which I really bought for the DTS tracks. They sounded incredible. When I finally purchased a universal player, I was a little disappointed by the sound of DVD-A and SACD. I expected it to be miles ahead of DTS, just as I had found DTS to be miles ahead of redbook CD. It wasn't. The sound of SACD and DVD-A was just a little bit more spacious, a little bit clearer, a little bit more detailed than DTS.
This, I've learned, is due to the fact that I have a low- to mid-end receiver, and a budget universal player. I've been told that had I gone with one of the more expensive players (a Denon 2910, for example), I would have heard a more dramatic difference in SACD and DVD-A sound quality. Some say that lower-end universal players have output quality only slightly better than CD to begin with.
Don't get me wrong. I think SACD and DVD-A sound incredible, particularly if it's multi-channel. But if all you've heard so far is DTS music, don't get your expectations too high.
cheers,
supervij