So a bit more to think about
:
I'm one of those that considers a total cleaning immediately after a brew to be an important part of the process... I clean out all the 'cat-barf' by hand and spray down everything with hot tap-water from a hose and pump that through every connected part and down the drain, and then fill the BK with 5G of clean water, add my PBW and heat it to 130° and pump it through everything for 20 minutes or so, with the out-valve feeding a bucket in which I have a much more powerful submersible (expensive--NOT pond) pump feeding a CIP ball that I hang from the inside of the keggle lid; an SSBrewtech 1.5"TC Brewbucket lid that's a perfect fit for the 303mm opening. The MP-15RM has nowhere near enough power for the CIP ball.
I mentioned the 3/8" bottleneck of my CFC...most inexpensive CFC's come with that 3/8" interior. If you want one of the 1/2" CFC's, they won't reduce your flow rate, but they're unlikely to fully chill in one pass either. I'm currently building a dual-CFC to replace my single-coil to reduce that bottleneck, but I don't believe my MP-15RM will have enough power to give me a good whirlpool going through that much line, so I bought a Riptide, in part because I found one at a very good price. I'd have preferred a Spike Flow (mainly for the nicer/neater bleeder valve). In testing it through my current setup, it provided an adequate whirlpool of 12G even through the 3/8" CFC so that's a keeper for the uprgades I'm working on...plus; it seems to feed my CIP ball OK. When you consider your potential CFC, first check your ground-water temp. Mine's 58°, so with my approx 33' CFC it drops to pitching temp in one-pass.
Just more fuel for thought.