So, after 3 days with my new Inspire PSE 300B, I could not be any happier with the amp. I'm stunned in the improvement over my trusty Coincident Frankenstein monoblocks that have defeated all challengers for the last 5 years.
Specifically, the areas that PSE bested the Frankensteins were the lower midrange, the power and clarity of the highs, and the simply huge amounts of air and space around the instruments & performers. The soundstage also expanded about 20% in width BUT at least +50% in depth. Downsides? The only one I can come up with is the amp does run hot but that is the logical outcome of having 4 300Bs and a total compliment of 10 tubes.