The Adagio has gone through a few versions. I have heard them all. Shane is correct about the tweeter but from experience, the later version does not seem to be as bad as the crossovers helped a lot.
I also prefer these with tubes and the more power they see, the better they perform in regard to dynamic speed and attack. The Adagio JR's do a better job in my opinion as the bass is tighter. They don't go as deep but I prefer the tightness. If I were to choose between the two, my preference would be the Jr's.
I still have a pair here that still need to be shipped out to a customer but they don't count as they have all new upgraded, external crossovers.