Dialogue HP all day, not even close. PL better musicality, greater bass control and since of air. Plus auto biasing and ability to tube roll. Using Meridian source and Magnepan 20.7’s.
According to the ARC website the VT80 is auto-bias and can take different output tubes from the 6550 to the KT150. Even has output tubes have fuses. Not many roll options for the 6H30 though.
Looks like they are trying to make their tube amps much more user friendly.
I haven't heard either. I think the VT80 is fairly new.