dts 5.1 fold down to stereo better than cd?

I have an Oppo BDP-95 connected to a 2 channel system. Does anyone have an opinion on whether the dts 5.1 DVD-A version of an album folded down to stereo sounds better than the cd version of the album? Thanks in advance.
I have a Ayre C5xe-mp and play my 5.1 SACDs, DVD-a's and DTS 5.1's on it and feel that they do sound better, much better, than the redbook versions. So I assume that you would get similar results on an Oppo.
Is it dts 5.1 or is it DVD-A? Not the same as the former is a lossy format and the latter is lossless.

Thanks Theo.

Kal, It is one of those that have the dts logo and 5.1 Music Disc in red across the top, front and back.

The label according to Amazon is Digital Sound but is has a Capitol logo on the back. Amazon calls it a DVD-A but I don't see the DVD Audio logo on it.
It is unlikely to be a DVD-A and the mixdown is, imho, unlikely to be superior to CD.
Thanks Kal.
Click the "i" button on your Oppo remote and it will tell you whether the source is dts or mlp as well as the sampling. I presume you are linked to a monitor as the default layer of a DVD-A without selecting could be anything depending on the disc. Also go back thru your setup menu to be sure which 5.1 defaults you have selected.
Thanks for the tips Oldears. I hook up my computer monitor if I can't get it to play 2CH blind. There is also an Audio button on the bottom of the remote that pulls up the MCH or 2CH menu and scrolls through the choices. Of course you need a video screen to actually see the menu but the Oppo display will tell you which one you're playing.