Other than Derek's review, which actually turned out to be more of a general plane choosing pointers article, there has been very little posted about these planes. I am wondering why?
I bought a #4 recently and I am very happy with it. My main concern with the custom planes was weight. They seemed very heavy. As it turns out the #4 does not feel heavy during use to me at all. I ordered mine with a custom 42 degree frog, following Derek's lead. I am amazed at how well it cuts just about any grain. Sharpening is easier, set up and adjustment are easy. I have a new favorite #4, easier to use and works better.