Update: I have around 150 hours on the amps and they are sounding much better! They opened up nicely with a refined natural tonal balance, good separation and layered depth. Bass is tuneful and goes pretty deep, very good for a SET amp. The midrange is starting to really sound organic with nice flow. Highs are extended,airy, with a natural decay.
Notice I keep using the word natural, because it is the opposite of cold, dry, thin, grainy, sterile, hyper detailed sound. Don't misunderstand and think the amps are slow, syrupy, and lacking detail. Further from the truth, it just portrays acoustic music in a natural believeable way.
They are keepers and supposedly will get even better with more time!
Joe