I have friends who breed them, and holy cow am I in love with their dogs. They are sweet as sugar with people; all their dogs, including their intact ones, can be loose together; none are reactive to outside dogs that I've seen. They run agility with several of their dogs, and are very competitive in their height classes, but they are very willing to admit that snuggling on the couch is pretty much what their dogs like best.
You do have to be careful with health stuff, but my understanding is that the life expectancy of the breed is increasing. One of their dogs is still running very well at 9, and I was just reading about one (not theirs) that just retired from agility at 12 due only to deafness.
After getting to know these dogs, I would not be shocked if at some point in my life I wind up with one. They just seem like the perfect house pet.