Thanks a bunch for the report. I brewed yesterday and the whole time was daydreaming about that thing. I got about 72% efficiency but I also did a fair bit of poking and stirring. I don't much care about maximizing efficiency, but I do want consistency and less fiddling around. If I could walk away from the mash entirely (after it's homogenized) and get anywhere in the 70s I'd be a happy camper.
I had a scare early in the brew day when the provided Topsflo pump would not start! I had to drain the kettle (preserving my modified water) and pull the pump out for inspection. After taking it apart and reassembling, it fired right up. Not sure what the problem was.
I was glad this happened though because I learned something... the pump is intended to be take apart over and over. I had always cleaned it fully assembled and was worried about getting water in the electronics, and as such didn't probably clean it so well.
Well, the moving parts are 100% isolated and easily detach from the motor housing. You can pull the metal part off and soak it in PBW, or disassemble it entirely and remove the impeller. It was a piece of cake, and all the fasteners use threaded metal sockets, so you won't wear them out with repeated reassembly. I was pleasantly surprised.
This may be obvious to y'all but this is the first brew pump I have owned and I was gunshy about disassembly. The manual showed the process, but it wasn't until I tried it that I realized it was no big deal.