I love my Americans! They are more "spirited" than many other breeds, but having actual personalities is a big plus in my book. I as well don't subscribe to the theory that crossing in black could possibly improve the blue color. Unless you account for how it is even easier to see scattered white hairs on a black animal than it is on the blues. Anyway, mine seem quite heat tolerant which is very important to me. And they happily breed year-round, unlike some other breeds I've tried that have been finicky about both winter and summer breeding. I'm starting to work more on improving the coats in my lines, that's currently their big weakness (and seems to be the big weakness of the breed in general, at least out on the west coast). But there are so many positives, such as large litters, great mothering abilities, the heat tolerance, interesting attitudes, and respectable enough growth rates, that I put up with fur that would be laughed at by a serious NZ breeder.