I finally had my first brew day with the new system this weekend! It went pretty well. My recirculation got stuck once or twice so I had to stir it up to get things flowing, and I don't really trust the mash temperature as every thermometer or probe I used gave me a different number in a different spot, so I'm just hoping for the best on conversion. I got 79% overall efficiency on 12 gallons, so I'm thinking it was okay.
The counterflow HERMS coil worked great for heating and chilling. I put 15 gallons in my HLT and my BK the night before, treated the water, and let it sit. On Sunday morning I had to be gone until noon, so I just set the HLT to 155 and ran it one way through the coil, and circulated the water in the BK the opposite way to heat on its own (so both could get up to temp while only having to set and fire the HLT). According to my logging software it took about 1 hour to get the HLT up to temp with the BK trailing about 10 degrees until almost an hour after that. Probably a wash in terms of time, but I was gone all morning anyway so it was ready when I got back.
After the boil I was able to get the BK down to 150F in about 5 minutes using the coil as a chiller with groundwater running through it, did a 30 minute hop stand, and then I got it to 65F in 25 minutes after that.
Draining the BK with the copper manifold I built was really slow, but it came out pretty clear. I think I'll replace with just a dip tube and a strainer of some sort and see if it's any better next time.
12 gallons of pale ale is in my fermenter, pitched about 12 hours ago. Now it's up to BrewPi.