Palermo?

I am currently in the process of planning a 2 week trip in September of next year. We have a very vigorous trip planned so far, meaning in 2 weeks we are starting north and going all the way south. The travel agent we are working with has us planned for a 2-3 day stop in Palermo on our way to Taormina.

My question is, can anyone offer any advice on if I should cancel the Palermo part of the trip and add it to our days in Firenze or if I should keep it the way it is? I have never been to Palermo but I've been to Tarormina. I've also been to Firenze but I was hoping to make day trips to nearby areas I haven't yet visited. Also, this is my travel companions first trip to Italy so their priority is a lot of the major touristy things.

Any advice is much appreciated!

Grazie!