As it happens, some AVS'ers were discussing why films no longer need the THX re-eq mode:
http://www.avsforum.com/avs-vb/showthread.php?p=19780460#post19780460Originally Posted by FilmMixer View Post
"I attribute that to better production techniques (i.e. learning how to wield digital processing and 5.1 properly, and moving from both 35mm magnetic recording and into good sounding digital equipment throughout the entire post process), improved tuning standards and B-Chain electronics..
I'd say once we got past 1997/98 we were in much better shape in regards to out of control HF content."
IMHO, use Cinema for 5.1 TV and films, discrete for DVD-Audio, Trifield for music. Those are my "rules of thumb".