There are two types of mozzarella cheese I use for pizza: low-moisture mozzarella (the shrink wrapped stuff), and mozzarella di bufula. I very rarely use the very fancy sounding fior di latte (fresh mozzarella from cow's milk), for various reasons. Primarily because I don't like the way it melts. Where mozzarella di bufula turns into rich, luscious blob of cream, mingling with the tomato sauce, fior di latte just sorta almost melts, and can turn a bit rubbery.
Disdain for fior di latte on pizza be damned, I grabbed a hunk of fresh mozzarella from A Family Affair Italian Deli, in Fair Lawn, NJ, just to see what would happen on pizza (and because I wanted to try Eddie's mutz).