Both health and temperament issues are rampant in King's Ransom Dobermans. We've had many come through rescue (Doberman Rescue MN).
If you are looking for a puppy in MN, I would recommend you take a look at Jaimand Dobermans: Home
If you're willing to expand your search further outside of the state I'd be happy to recommend some other breeders, too. You can do SO much better than KR.