Super Compact arrived. Initial impressions:
1 - Nash JB63 > Monique > Crown XLS1000 = meh. No lean and mean J bite. It is dark and congested

I moved the EQ all over and couldn't get a tone I loved. I added some comp and chorus, even a little overdrive, but no magic showed.
2 - Nash PB63 > Monique > Crown XLS1000 = meh. It is dark and congested

I moved the EQ all over and couldn't get a tone I loved. I could get some growly grind, nearly distortion I've not heard through other cabs. I found a lower-than-usual Sensitivity setting was best, with the bass turned way down and the highs and mids cranked. Still, not in love.
3 - Nash PB63 > Buster 200 =
BINGO! Add in the Pork Loin, and we are off to the races! I think this is going to be the keeper. The "solid state" tubey brightness of the head lights this cab right up.
4 - Nash PB63 > Walkabout = Pretty good. It's a happy mid-point between the Monique and the Buster. The EQ is mighty, so I think I'm going to dial in things after some more toying around.
5 - Nash JB63 > Walkabout = Even a bit better. I generally like the J better than the P with this head. I got some of what I was after; the J-ness came through.
Overall, I'd think the darkness I hear is because this is my first cab without a tweeter or mid-driver. The lows from this little guy are just nutty. They can get a little bloomy and big, but the EQ and gain settings seem to have a pretty big impact on how the cab behaves. It strikes me as a very "British" feeling bit of gear; it liked being pushed a little when playing along with Judas Priest, and The Sword. It is also quite sensitive and loud. It made the Walkabout's notoriously slender wattage seem like it might stand a chance with a drummer and just this cab (though certainly not in any setting where you'd need a 610 or 810).
Also, I shouldn't miss the fact that it is stupid light and cute as a button.
I'm pretty happy, though a little uncertain that this is the tone silver-bullet. I'm really hoping the new Peavey MiniMega pairs well.
Enough typing. More playing. Back to the lab.