ALL true. Even the “subjective” stuff you said, I agree with. So this is what makes the MT15 all the more impressive.
Here’s an example of how all this plays out in the real (amp) world. People have for years raved about how loud Dr. Z amps are for their rated wattage. These amps mostly have small power tubes. Lots of EL84s. But people rave about how loud they are for 18 watts or 36 watts or whatever they’re rated at. Same with Vox amps. My AC30 will blow your ear drums.
Science DOES matter though. Push the mids forward, your amps sounds louder. (I prove this EVERY time I re-EQ the Archon from “Scooped” to “ flatter” because I immediately have to turn it down). So an amp with big bottom end will run out of steam way before an amp with a flat bottom end... and one with rolled off bottom can get crazy loud with a power stage rated to put out “moderate” wattage. If you understand how power amps work, it takes many times more power to put out lower frequencies than even low mids, which explains all the above. Roll off the bottom end and hook up two highly efficient speakers, and a 30 watt AC30 can blow you out of the room, while a 50 watt amp may not be as loud. But try to play something that needs big punchy bottom on that AC30 and it won’t do it.
I read something years ago in an amp building forum that said VOX EQ curve was like an upward slanted line, Fenders (Blackface) was a smiley curve, and Marshall was the inverted smiley curve. Most Dr. Z amps are EQ’d similar to Vox so they have little bass, but again everyone raves about how they “cut in a band.” Yeah, all mids and highs DOES cut. Those chugging power chord amps that have punch and bottom and flap your pants, dont “seem” as loud as the amps with mostly mids and highs. Which can easily get loud with much less power than the amp that has big punchy bottom.
Rambling, so I’ll stop now. But all this is relative to the MT15 which people say has tons of punch and bottom end and volume... none of which go with small tranny, small power supply cap amps.