This system is similar to mine, except that I use a 48qt ice chest for the mashtun, and have a regular old coiled wort chiller. Five of us built the same systems about 12 years ago, based on what one of my friends had seen and used with another buddy.
I like the ice chest for a mashtun, as it holds temp really well. It is also shorted, so the overall height of the system is shorter. My mashtun has two copper pipe maifold, witha lot of sltis made with a sawsall. One manifold is on top, and acts as a sprinkler. The bottom manifold takes the runoff out to the boiling keg.
My chiller works fine, and is easy to clean. When I get real fancy, I put my old 5gal wort chiller in a bucket of ice water. I connect the hose to it, and then another hose over to the chiller that's in the wort. It works great that way.
By ez-mash screen, do you mean that screen filter thing that Jack Schmidling sells? I think that tool takes too much of the sweet wort from one spot, instead of the entire grain bed.
The lower manifold in my mashtun runs basicall three pipes along the entire length of the grain bed. So, I pull sweet wort from the entire base of the grain bed; I think that works much better, but that is IMHO, as I have not tried other methods.
I think my manifold approximates what a false botom does, in a rectangular ice chest.
The system your buddy has is a great setup. I'm sure it works great. I think my mashtun probably is easier to work with, but either step should work just fine.