Update
More info, and a few experiments:

The 78 had a West Marine 150 combiner, which has a little label hidden on the back that said it was a Yandina and it needed the "minimum six feet of 6 gauge or less wire" connecting it (which it did not have). The Yandina site says this particular model is discontinued. I bought six feet of 8 gauge wire, split it to three foot sections and moved the Yandina/West Marine unit to the 75, keeping the isolator. Wow, 8 gauge was overkill, and too stiff to work with easily. I forget (have read on here before) why the six feet is needed.

I installed the new victron combiner in the 78 (no isolator). It did not say anything about six feet of lead wire, so I used the previous connectors.

Yesterday I worked in the 78 with all the interior lights and running lights on to load both systems while I fiddled with a new rotor, cap, timing and bunch of other systems. It did cycle the combiner, but not too often, and the noise is less of a clunk. With only the house side loaded, it seemed to cycle less than the Yandina.

I paid about $50 for the Victron, and Jim K has the Yandina 100 for $65 with the wiring premade. The Victron does not have an indicator light telling you when it is combining, the Yandina does. I think I would go with Jim K's Yandina if I were doing another one, both are a nice addition to stock setup.