DVD's with only audio capabilities...huh?

I was in Tower Records the other day and, next to the SACDs, I found a section of audio CDs that can only be played in a DVD player. It seems they are digitally mixed for a Dolby 5.1 format. They also said that these DVDs would sound better even on a two channel system as there is more detail recorded on them. I must admit that the music DVds have often sounded better than standard CDs. I bought three of them and I am playing them on my Marantz DVD player and using my Audio Aero DAC to feed a two channel system. The Audio Aero does register more information coming through than on a normal CD. They do sound nice, especially the Bachman Turner Overdrive, 'From the front room'. I came home and did a discussion forum search on Audiogon for 'DVD AUDIO' and found some talk about how good it sounds--at least as good as SACD. When I think about it, this system might have a better chance than SACD as so many people already have a DVD player. Has anyone with a really high end system tried this format...what do you think?
You will find DVD Audio in hundreds of the old AudiogoN threads as DVD-A

DVD-A is the designation the same as SACD is to Super Audio Compact Disc.
Just a further note ... to get the full benefits of DVD Audio, you would still require a separate DVD Audio player. When you play DVD Audio discs on your standard DVD player, you get playback from the 2.0 DTS layer ... you do not get the full blown DVD Audio experience ... for what it is worth. I would think that one of the inconveniences of DVD music playback (for both types of DVD's) is that you often tend to require a TV monitor to assist in disc navigation, etc.
Sounds like audio DVD-Video discs. I have a few of these disc from chesky records that are recorded in 24/96 resolutions. These disc sound great when played on my DVD player. I have not tried them on a normal CD player.
My current system can spot a poor CD recording. For instance 'The Best of Cream' Cd was a waste of money. The latest release of The Band's 'Last Waltz' sounds terrific. I found a DVD-A copy of the 'Last Waltz' and I can't see too much of a differance, but I think this is more of a limitation of my system. My first impression as I noticed it in the record store was that this reminds me of the gimmick of quadraphenia, from back in the early 70's. Still, I wonder if someone with the best capabilities has tried it. Also, is there really that much more to needing a DVD Audio Player, as opposed to just using my DVD player. I logged into the Silverline web page and it seems they are going to try to market it to the automotive industry. This would be quite an interesting effect. Five channels in a Lexus.
Left out something else ... both the DVD Audio & audio DVD Video discs are not playable on a CD only player. This is why there are more "universal" machines making their way into the market. Most consumers do not have the appetite, let alone the room, for multiple digital sources.