Lesstew,, I guess the answer to your question is yes and no (laugh). I believe all the trains to Florence do stop at Pisa...but there are also some trains that go to Pisa and do not go to Florence. You also need to keep in mind that a stop in Pisa will probably take at least 90 min...and that assumes you don't try to get a reservation to climb the tower. Its a good 20 minute walk from the station to the tower although a taxi will save you lots of time. I think most tend to stop off at Pisa on the way to Florence and than plan on getting to Florence in time for lunch. But, if you have never been to Florence you will find that every minute will be precious. Its a relatively large city with so much to see. In fact, i seem to recall that one of the major travel magazines (might have been Conde Nast) called Florence the number 1 tourist city in the world.