The GE and the road to recovery
I'm wondering if the water solenoid was restricted by some sediment and dind't get proper full water fills.
It had a new water valve that was known to work

The GE did get its full fill of water; it just sucked. No excuses
It was 30 years old, though, and probably had never had the sump cleaned from years of chicken bones and broken glasses, so I'm sure the pump performance suffered. I couldn't work-up the enthusiasm to tear it apart and clean it out, though, because A) it was ugly and B) the sump has about the structural integrity of Rice Krispies holding hands. (It's about to rust through completely.)
Nevertheless, the GE design--in more TOL machines--was probably proven, and the Power Shower would not have hurt with the top rack top-down coverage.
Disconnecting the Calrod just made cleaning worse lol.
I wouldn't be surprised. In our case, I saw no difference in the lack of cleaning performance between the time that the Calrod was on and when it was disconnected, but we have really hot water here anyhow.
The D&M was a work in progress. When first found, aside from being disgusting and every conceivable kick-panel and trim part being bent, dented, or broken (it seems people get confused by the kick-panels on these machines--they don't pop off, and don't come off via screws from the front--you have to get at their screws by opening the door, and a lot of people pull and pull at it out of frustration), it was noisy and leaked from the motor. (Obviously, not a good under-counter candidate.)
Turns out, someone had broken enough glass in this machine to make new sand for a beach. All around the tub seal was a sparkling sea of glass bits, crushed and recrushed over time, probably by the macerator. The spray arms had chunks of glass in them, and also little tabs of black plastic that solicited a hearty "what the f--- is this?" as the machine came apart.
Of course, those little black "tabs" were vanes of the drain impeller that had been blown off the impeller disc by a few sizeable (sturdy) chunks of glass. The now-wobbly impeller, Roger theorized, probably contributed to the decline of the porcelain-carbon seal for the motor.
The good news is that D&M parts are CHEAP (you can get an entire new mechanism--minus the spray arm and the motor--for about $50), and so I was able to get a seal kit that came with new impellers, O-ring, shims, new carbon seal, new porcelain seal, and a shim feeler. That fixed it beautifully, and made it run the way it should (minus the vibration and minor waterfall from the motor.)
Further cleaning, bending, and fixing yielded the results you see
I was tickled by the parts bag for the seal kit, though. Since when did Electrolux claim Kenmore as one of their own brands?

It makes sense, but this was the first bag I'd seen that listed Kenmore right alongside Tappan, Kelvinator, and friends.