Well, I could tell you my personal experience with a BYB (Nova is from one). Although, it's not very exciting lol. She just has really bad allergies -- recurring rashes and ear infections. They are uncomfortable for her and cost us lots of money. We've already spent way more on her in vet bills than we ever would have if we just spent the $800 up front to get a well-bred dog, and we've only had her for 7 months. We didn't know any better, though, and either way she is still the light of my life

I know of some real horror stories with Puppy mills. I'll try to find them and post them for you. I may not have saved them, though.