This thread has been done before, but i'll tell you my experience of the subject anyway.
Bought three pups off the man about 3 years ago, a dog and two bitches, the dog had prick ears and one testicle, not the end of the world but he was better suited to a pet home, so thats where he went. one of the bitches was useless and only wanted to fight other dogs, the other bitch started work after 2 years but was hit and miss and also wanted to fight other dogs all the time.
None are with me and my mate any longer.
PS one bitch showed early promise but it was not to be.