I very much agree with what has been said already; this is not necessarily a course to seek out by itself. But it is a fine member's club in a small town. Also, as you say that you are interested in Diddel's trajectory as a designer, I think you should definitely visit Ulen.
My grandparents were members here until they died and it was the place where they first introduced me to the game of golf. There are a couple of interesting holes, and a few head-scratchers. There are a couple of sharp doglegs, for example (which seem to underscore the routing limitations on such a small site) as well as the 9th hole which never seemed to set up well for me and I end up playing my second shot from the parallel 18th fairway or from the neighbor's pool on the left!