I believe that meeting the standard of quality required for THX is less of an issue today than it was a decade ago - companies like Outlaw, Rotel (whose RSP-1066, 1068, and 1098 lack the THX certification that Wayne's older RSP-985 offered), and numerous others have chosen to build hardware that offers very high build quality and performance without relying on THX to "check their work". It is this aspect of the THX issue that leads many people to write THX off as "just another sticker" - with a little research (a relatively straightforward task with the Internet available as a resource), consumers can find hardware that costs quite a bit less than comparable THX-certified gear and is reasonably comparable in build quality and performance. Credit must of course be given to THX for helping quantify some of the design goals incorporated into all worthwhile modern gear - it's just that you don't necessarily have to buy something with the THX logo on it to get a piece of equipment designed with those goals in mind. The one aspect of THX licensing that you still only get with the THX logo is their specialized surround processing (the software described in parts 2 and 4 of Brian Florian's THX article). As Wayne very accurately summarized, some of those features are also available outside the realm of THX (re-eq being the principal example), although some of course will be missing from the Model 990. Even without those, I still suspect that the Model 990 may prove a good fit for your system.