Just going to throw a couple things out here and see what others think as well ...............
Some of the problems I've seen brought up on here are staggered set ups not having the extra supports, resulting in cracking/leaking at the flanges due to all the extra weight of all the pipe it takes in this engine set up, some say the extra braces installed at the rear of the engine cure this.
Heat problem at the flange where the pipe is welded on, resulting in a similiar type of failure. This seems to be more in the earlier style that did not have the "cool collar" design that allows for more cooling water flow closer to the flange. It has been said that this newer design, "cool collar" style, is not prone to this failure.
Not saying this is gospel here, just some of what I've picked up on thru the threads related to this.
I have the newer "cool collar" style, side by side set up, with the silent choice option on the Fountain and so far have not had a problem. At least not that I'm aware of at all. I do agree with Ray in that at times things on here do get expanded a bit beyond what might be the actual deal.
Question here for Ray ........... Is there a way to tell if you have an internal leak or water reverting back in an engine that seems to be running fine? I realize that this will often show up on tear down, but can you tell otherwise?