I just installed one on my PS205. It seems to work well, the boat ran fine and there was a lot of water moving through the system. I didn't see any heating problems either.
Super easy to install, it clamps down on the intake water hose, so i don't see much chance of it coming loose. The design itself seems pretty simple and I don't think it will fail, but I will keep an eye on it.
According to my dealer, On the Edge in San Diego, they install one on every Mastercraft they sell for ease of service.