I’ve always thought they were so cute. My sis-in-law had a miniature. He was tenacious! Didn’t like anyone but her, though. My brother-in-law used to call him a football with teeth! :)
I can see the tenacious side sometimes. But. I specifically waited until I found a mini that was very calm. That was our over-riding factor. We found the perfect one. He is the sweetest, most gentle puppy I have ever been around. He loves jumping in peoples laps and taking a nap.