I am a guy with a number of vintage amps, including 4 Princetons
This amp does everything correctly, every knob seems to behave very well..
The Sportsman does the lower volume crunch, if required , unlike any of my princetons.
The headroom does act as a master volume amplifying whatever gain needs you have dialed in with the first volume knob... the treble does not get too brittle, and actually becomes quite diminished in function when the midrange pot is dialed up...
I just played it tonight direct, using no pedals with a Gibson custom shop 329'. It supplied the range of tones needed without footstompin the pedals like the other player were doing all night.
I have also used it with my pedal board, driven by many different guitars in my stache. Good with pedals and every pickup combo as the amp cleans up beautifully, and can go low to Db's just dialing in the gain to taste with Max Headroom controlling the presentation.
The tubes, are very much out of the way from any wire cargo that typically slams and slants the verticle hanging tubes in all my other combos. I have the early tweed amp number 06. I feel the tubes are recessed enough so that they do not seem to be in harms way.
Thanks AC / Florida