Thanks. It was a fun build. Took a little longer than I first anticipated, but some interesting challenges. I'm happy with how they turned out.
They're done, wired up, and playing. No surprises or issues mounting the drivers and doing the wiring. I started breaking them in..they sound very clean. They do sound different than my panel speakers, but no surprise there. I'm running them off my (Don Sachs D2 preamp and) McCormack DNA-1 power amp for the moment as that is what powered my previous speakers. The amp is serious overkill for the coax drivers. The DNA-1 will be going into for a rebuild in a couple months. I'll insert the Sachs Kootenay in for power at that time and see how they sound.
But..I'm in and out traveling for a few months and won't have much time to mess with them. The speakers need many more hours of break-in before I can really offer an opinion.
So far, so good. I'll update when I get a couople hundred hours on them.