Thanks, this helps. I'd like to get into a fridge-replacement solution that sounds fast and hits pretty hard. There, I think that's the TL;DR version.
Long version: I play for a Christian Metal band at my church (we play covers from Disturbed, FFDP, Papa Roach, among others and change the lyrics) and have an unreasonably large stack for our theater. When we practice (in a separate space) I'll use my GK 700rb into my Henry the 8x8. The other day I heard some HF distortion coming from ol' Henry - but I haven't yet determined if it was my amp, the cab, the room, or ?. I appreciate the transient response that GK's RB series amps deliver but I'm also being conscious of Henry's limitations (I can still get it pretty loud though). Hearing that annoyed me, so when I have time I want to play around with some other amps to figure out what is going on.
Anyway... I've had the opportunity to play around with different combinations between it, a Mesa 400, and an Ampeg 810 (Pro series, which are still sealed cabs but deeper - and weigh 220 lbs

). I prefer the Mesa atop the fridge, and the GK with Henry. The Henry rig sounds tighter; the 10's in the fridge sound "woofier" if that makes sense. A little looser, less controlled - even when powered by the GK.
Our first show in a few moons was out in Texas back in February. I brought both stacks. We were indoors, playing to about 150-200 people, in a room with a stage, say about 5k square feet? Bass was not in the PA, and I was mainly in the Mesa/Ampeg stack, but also ran the Henry/GK stack next to it to add a little more oomph (how often do you get asked to turn UP at a show? Not me - so I was more than happy to oblige when the sound man said he wanted more bass

). It was loud and sounded great.
What's my point? It would be nice to have a simpler solution as that was the second time I played with the Mesa on max clean (and it is pretty darn loud in it's own right). I'm curious if the 66 + 110 would get me there. Or if updating all the 8" drivers in Henry to Dayton's ($250-$300) could add some extra volume but still feel "quick".
Or maybe I don't play enough and am just a bored gearhead.
Next month I'm traveling to MN to retrieve a PJB rig I bought remotely and had a buddy pick up and store until I get there. I intend for that to be our sanctuary rig going forward, if I like it. If not, I may flip it and look for a MAS rig. Or look for a MAS rig anyway, if I have any $$$ left after the trip.
So that's my story and I'm sticking to it. If you got this far, thanks for listening.
Eric