I too have tried many of these configurations and have speakers with quite a bit of midrange information (even a crossover around 150hz goes really far up if its a first order slope). Unfortunately, I always lost too much coherency for it to be worth it. The different amps muddied the woofer to midrange crossover and the music fell apart. *This was even true when the amps were identical and fed with the same (split) rca input.* Even with perfect gain matching and identical circuits, just using independent circuits for the woofer and midrange/tweeter created enough differences that I eventually went back to a single amp per channel. I do, however strongly believe in monoblocks with separate amps and power supplies for each channel. And I do have separate amps for my subs.
Obviously plenty of people love their biamped systems, but just be aware that YMMV.
Obviously plenty of people love their biamped systems, but just be aware that YMMV.