Piccolo forno is, hands down, the best value for food in the city that I have come across. I've been half a dozen or more times since I moved to Pitt and Piccolo Forno has never disappointed me. If you've never been before, at least one person at your party should order the marscapone y speck pizza to share with the group. It is simply delightful.
Portions are extremely reasonable- I'm a normal sized, younger man and I'll eat 6/8 slices at dinner and not leave hungry. Prices feel extremely low (13-15) for a pizza of such insanely high quality. BYOB makes this place the highest value restaurant I can think of.
The only downside of the restaurant is that they do not take reservations. They will, however, call you so what I've always done- either in a group of 2, 3, 4, or 6, is to place the reservation and head across the street to round corner cantina to enjoy a drink while we wait. I recommend you do the same as the wait will often be 30-50 minutes if you arrive during prime time.