Sounds is pretty darn good so far. I finally got around to flipping the cabinets (placed them on some floor dollies), and that definitely helped to further blend the the horn with the 412c. I also picked up a pair of RCF H3709 horns for cheap, and I hate to say it, but I do prefer their sound over the 811s. I'm probably heading down a rabbit hole that will eventually lead to 32s.
One thing I've been doing is flipping back and forth between the crossover I built and a simple 1.5uf cap to the 806a. Both approaches seem to have their own merits sound-wise, but I think I prefer the crossover a bit more in this particular configuration. One thing I'm considering is building a second pair of crossovers using better quality parts--mainly using PIO caps instead of the inexpensive polys that are currently in there. I've got a lot of experience building amps and such with classic PIO caps like Vitamin Qs and old Russian stock, but I've never used motor run caps before. Are there certain brands that are preferred for one reason or another (reliability, etc.) or are they all basically the same when used in a crossover? Looking at various sites that sell such caps, and prices seem to be all over the place--you can get a 10uf motor run cap for $7 or $40, but I have no idea if the more expensive ones are better or not for audio applications.
There's my N1600 clone which I used when I rolled off my 414As. These are loaded with Sprague PIOs and Russian MBGO wax/paper in a metal can (smallest and rusty can).
Here's another one I made with Sangamo PIO + motor