Although not the prevailing strategy for biamping bass...I only get good integration when you use at least the same type of amp (SET, PP tube etc.) on all drivers or even the same amps on all drivers.
I haven't heard an active commercial offering that I would want to own. I someone comes up with one that is high sensitivity and is driven by in-built SET or similar amps and a DAC that doesn't use an ESS sabre chip...then I might be interested. I think the closest to my own ideal would be the...
I have considered the Marchand tube crossovers...I agree with you that I have yet to find a SS active xover that was truly transparent (two different Accuphases and a Bryston). The digital solution I came up with, where I use my own DACs that sound much better than what is typically integrated...
You need 6 stereo amps?? Or 6 monos? You could get 3 Aries Cerat Protos or Genus for well under 100K....You wouldn't even need a preamp as they are integrated. You could get 3 Ayon Crossfires used for about $15K. Just some examples... If you can't hear the difference that would bring...
When I was a level 27 Audiophile I wielded the Infinity Turntable, which spun forever at exactly the right speed by the force of my audiophile greatness!