DTS/DD - 80's, 90's,,,,today

I recently purchased the Al Dimeola, Stanley Clark Jean Luc Ponti,,Live at Montreux DVD. The concert is from 1994 and to me is one of the best music dvds i have purchased. I run it Dts w/ PLIIX. The sound staging is amazing. I feel like i'm in the middle of the audience with everyone else.

My question relates to both movie and music dvds. I am using the above music dvd as an example. Shouldnt a more current dvd (made 2003-2005) which is recorded in DTS sound better than a DVD that was originally recorded in stereo and then re-engineered into DTS? This was always my thought process but after listening to the Al Dimeola material from 1994 i am confused. For example, Motley Crue Carnival of Sins dvd (2005) which was recorded in DTS. I find the overall sound is boardering on ok. Actually a big disappointment after waiting for it to come out. Is there a rule of thumb that one should follow when purchasing older source material that is now being released in DTS or does it just come down to how it was originally mixed??