It depends a lot on the version of DTS. The movie Theater version at 1.4Mb is very, very good. You find those on rare special DVD disk editions (when it is the sole soundtrack). Unfortunately, on "normal" DVD, you mostly get the 768Kpbs version, which is not really better (and in fact might even be less good, at least according to DD!) than DolbyD at 448K. You tend to get DTS tracks on disks from producers owning DTS (aka Spielberg)!
SO far, and maybe it is the choice of movies I have, the DTS soundtrack has always sounded as good, or in many cases, noticeably better than the DD (which still is a great encoding). Some movies are just crap, or they slap things on them, but since DTS costs extra, usually (not always) it is an improvement.
As for Spielberg, I agree... As well as him,Universal has a stake in DTS, but both of those happened AFTER the DTS soundtracks for several movies won Oscars (AKA Jurassic Park to start, Saving Private Ryan, etc)
I used to look for DTS to be on movies. It didn't keep me from buying a good flick that "only" had DD. Usually the better movies had really great DD tracks anyway, but it was like an added bonus. I wouldn't pay more than a buck or two more for a DTS disc, but then again, I'm kind of cheap!
As for the other comment CV, where does it say that DTS uses a "less efficient compression than DD?" Not saying that is wrong, I am just wondering. It is usually less compressed, but that would seem to be a positive.
Again, not trying to dump on DD. DD 5.1 is great stuff. I just generally prefer the better sounding, to me, DTS versions when available. If DTS sounds like crap to you, then listen to the included DD. No harm... No foul... Life is good!
