Photo note: This came off the Internet. Look closely: this is VERY representative of the Min Pin's personality. A "red zone" dog with intense energy, a drilling stare, a lip curl ready to be displayed, and a foot raised in prep for a speedy take-off. Note also the totally inappropriate collar. While a prong collar is probably a very good idea for this little stick of TNT, the prongs on this collar are WAY too big and heavy. This dog could probably benefit from the mini-prongs, but nothing bigger.
First off, this dog is NOT RELATED IN ANY WAY to the Doberman Pinscher, so if you think you're getting a "bred-down" Dobie, forget it. The Miniature Pinscher (Min Pin) is a terrier (in fact, that's what "pinscher" means in German). She is a stick of dynamite, known for her barking, her quickness, and her aggression. This is not a breed for beginners, nor is it a breed I'd recommend for laid-back folks with small children.
The Min Pin has attitude. They're born with it, and it can lead to real problems unless they're given VERY FIRM DIRECTION AND LEADERSHIP from the day they come to live with you. Most vets don't like working on Min Pins because they bite when they're ticked off. Fortunately the breed doesn't need much grooming (the one BIG plus to them is they're low-maintenance in that department) because they usually require muzzling for procedures like toenail trimming and ear cleaning.
Although small and fine-boned, this is a hardy dog that requires daily exercise. The more the better, but give it at least one long walk each day.
Like many other terriers, the Min Pin is intelligent yet independent, and lacks that "will to please" characteristic you'd find in Golden Retrievers and Labs. A Min Pin is exceptionally smart and quick to learn; getting her to comply with your wishes, however, is another matter. Just because she knows what "sit" means doesn't insure that she'll do it consistently and obediently (and without bribery). Most Min Pins have a fairly high opinion of themselves, and they are not easily humbled.
This is a terrific guard dog. She will alert you by barking when someone comes to the door. She'll dart back and forth, barking or displaying teeth while the guest enters your home. She may come up for a sniff, if coaxed, but is likely to dash away again if the stranger reaches to pet her. If the stranger were to corner her and reach for her, she would probably bite.
If you're experienced in owning attitudinal dogs, and you like that feistiness, if you don't have small children around, if you are active enough to provide plenty of structured exercise, and if you are feistier and more attitudinal than the dog, then a Min Pin can be a good companion for you. They live a long time, don't eat much, and stay very clean. You MUST keep this dog on a leash when outdoors in unrestricted areas. They run quickly, get lost quickly, and can get hurt in fights if they stumble upon other canine marauders.
As always, my views are generalizations formulated over years of working with the breed in a training atmosphere. I can think of ONE very nice Min Pin, female, who never displayed aggression in public, who was sweet and willing, and even went to school with her grade-school teacher-owner. When it comes to Min Pins, I guess one in 15 years ain't bad.