Having owned CAT, Joule, and Atma-sphere, I would say that 6550c's observation should be given some serious consideration; you at least need to try a Passive - in the right system, you may not need to spend $18,000 to have SOTA sound. Try a Bent Tap-x for $1,000-$2,500; it is worth comparing to anything mentioned here (not that it would be your first choice, but for some, yes).