As a mother of young children, I would be highly concerned if a Pit Bull moved in next door.
I understand there are a lot of Pit Bulls, Rottweilers and Dobermans out there that have never done anything wrong, but every story I ever hear where a dog has attacked a person, it has been one of those breeds. The three that I personally know were all family pets. I have never heard of a Lab, Retriever or other well known family breeds, attacking someone. I believe there is a reason for this. Just as physical traits run the same in each different breed, so do mental traits.
I understand a lot of people own these breeds and love them. I respect that, but still don't trust those dogs enough to allow my children around them. It's just not worth the risk.