Apart from the noise outside (not all rooms) this was a great place to stay. The staff were extremely friendly and helpful and the breakfast was fantastic. The rooms clean and tiled (no dirty carpets). The locations was smack in the old part of town as well.

We booked this at quite short notice through venere.com. We are a family - two parents and two children - and so needed a quad room, of which few seemed to be available in Pisa at the time.
At Euro 160 per night and allegedly three star, we were expecting better than this. Basically the room was a double, with a single and a folding bed wedged into it with barely room to walk between them. It overlooked a building site and was clean but shabby. The bathroom was small but fine - power shower and plenty of fresh towels.
The breakfast was very average. Croissants, bread rolls, cereals. We were unimpressed that hot drinks came from a push-button dispenser. Some fresh-brewed coffee would have made us feel much better about everything.
The best thing about di Stefano is the location - just perfect. 300 metres from Leaning Tower and cathedral, even closer to major shopping, and 500 metres from the glorious produce market and river. Wonderful pasta/pizza joint over the road (Vesuvio).
We walked to the station (about a kilometre) and did day-trips to Florence, Viareggio and Lucca. Pisa is a great base to see this part of Tuscany.
The staff were helpful and friendly.
Try to book early for Pisa as it seems it's very crowded, and if you need a family room it my be better to call directly than to use a website - though the venere site was very efficient.

Spent 7.50 euro from the train station to get to a tiny cramped room and bathroom! Can hear everything that goes on in the hallways even over the loud drone and dripping of the mini-bar fridge. Take other people's advice and do not stay in Pisa- but do try the restaurant Osteria Del Tinti for warm salted bread and testaroli with nut and ricotta sauce!

This unpretentious hotel is situated in a narrow street handy for the Tower, not far from the main shopping street and some local bars and restaurants. The double bedrooom was quite small but very clean, bedding changed after 3rd night. ensuite also clean with plenty of fresh towels. Mini bar but no safe available in room. Basic continental breakfast only (juice/bread/jam but really good coffee. Owner basically ignored clients unless directly spoken to but staff on reception were friendly and very helpful. Booked via Venere and had no problems at all.