The mid selector is turning out to be cool. I've got the amp in the studio and playing to some tunes. Dock of the bay and the selection at low and it's thick and creamy and so clear. It just is there and so present. With some Elvis, I turn it to the middle and the bass just sits right perfect. Creedence Green River and turn the knob to high and right away there is upper mid grind. It's just right. Not touching any other controls and this mid selector has 3 usable points. I hope it translates to live shows as well.
edit: after a couple hours of playing, a buzz developed when I would hit the A right in the back of the cabinet. "Damn" I thought, "no, please no, the naysayers are dog pile all over this". Then I tapped the transformer and there was the buzz. I figured it was one of the screws holding the transformer to the chassis and tightened them (they didn't move much at all) and now there is no buzz. Crisis averted. It's been good since then. So, doing a little shakedown cruise type thing but everything is back to being groovy.
One more thing and I don't even know if this is a thing but, I turned the amp on at about 8 this morning and left it on since then, playing 45 minutes or so, switching into standby numerous times and letting it sit. Nothing is melting and nothing seems to be going wrong, so I guess that's a good thing.