I see three major problems with using THX as a standard for judging A/V equipment quality.
1) The difference between slight changes in component quality can result in small performance (read: better sound) improvements. There are so many variables involved that you'd really have to have a dizzying number of quality "levels" to use anything objective as a single litmus test.
2) The THX "vision" of what makes good sound is merely one group of individuals' preference. This hobby is inherently subjective meaning the THX vision may conflict with your own. An example of this would be direct versus multi-polar speakers. THX believes surrounds should not be direct radianting. I know plenty of people that prefer the sound of direct radiating surrounds... Relying on one group's definition would merely help to eliminate the variability that makes it all so fun.
3) The qualities required to meet THX specification are largely closed and certainly not open for debate. At the very least, you'd need an open governing body with representatives from all the major manufacturers, artists, studios, engineers, etc. along with open classification.
None of these will ever be resolved, so I suggest you buy what sounds good to you.
Regards,
Semi
