Is Pisa worth more than two hours?
Yes. Beyond the Leaning Tower, Pisa is a living university city — the Lungarni riverfront, a real food scene, and a relaxed evening passeggiata that day-trippers never see.
Most people give Pisa two hours and one photo. Give it an afternoon and an evening and you get a completely different, much better city.
What's there besides the Tower?
The Lungarni — the elegant palazzo-lined banks of the Arno — are the real Pisa, especially at golden hour. Add Tuttomondo (Keith Haring's last public mural) and the porticoed shopping of Borgo Stretto.
How do you time the Piazza dei Miracoli?
Go early or late to dodge the coach crowds. Book the Tower climb ahead; do the Duomo, Baptistery and Camposanto with the same combined ticket while you're there.
Is it a good base for Tuscany?
Excellent. Lucca is ~30 minutes by train, Florence about an hour, the Livorno coast a short hop — and beds cost less than in Florence.