As I wrote in an earlier post, we did a Norwegian Florence on Your Own excursion, but a do it yourself Rome from the Epic. We did save money for Rome that way, but there was a negative also. For Florence we had an air conditioned bus. For Rome, the train back was packed and very warm on a very warm summer day. And that was before a fight broke out on that train making it even more uncomfortable!
DW did say afterwards, maybe we shold have done it as an excursion.