I don't see anything terribly wrong, they do health test and show (though I don't know where they can be registered and shown, so not sure how competitive those shows are). They have two litters this year (one already born, one coming up), so unless they are planning more that's not too bad. I suppose you'd have to talk to them to find out more about their breeding and raising philosophies. The only thing I noticed is one of their females looks a little wonky int he front end and they are breeding her. Maybe I'm just seeing things but she doesn't look like an outstanding specimen. Most Australian shepherd folks don't agree with the creation of mini aussies, or at least don't like that they are called by the same name as they are so different from the Aussie and there is really no way to know if other breeds were introduced to create them. I personally don't have a problem with them, but they are not my breed.
Are you looking to get yourself a Mini Aussie?