I met a guy with a 6 month old male in a parking lot today. Wayyyy too cute!! This guy was an import from Minnesota. I had never heard of the breed before and Googled Munsterlanders when I got home. The most I could come up with is that it appears that they have a pretty high hunting drive, so breeders will only sell to approved hunting homes.
I only know what I've read about them, but would seriously consider having one. I first heard about them around 1980. The German exchange student who lived with us that school year had one (back home, obviously. )
BTW- there are two varities- the Grosser (larger) http://www.lmcna.org/ and Kleiner (smaller) http://smallmunsterlander.org/
I've got a friend who has one. Beautiful dog, very smart and friendly. My friend is a serious hunter and says it's the best hunting dog he's ever had. They've got a couple of cats and don't seem to have any problem, but they did have the cats before they got the dog so maybe that has something to do with how well they get along.