The way I see it is if you are going to be wanting to see a historial site (or whatever) that is not next door to the port, and depending on the time of year that you are cruising, hands down I would take the ship tour. On an organized ship tour, the ship will wait for your return. Also, with regards to stragglers on the tours (people who think they are more important that the rest and operate on their own time), we took a tour to Ephesus and a tour to the Acropolis (on both tours, we were given time to explore with a definite meeting time) and were given walkie talkies and we were told that if we did not return within the alloted time, the tour would not hold up the rest of the guests on the tour, and that the bus would leave without us. That is a pretty good incentive for people to return on time. We were all told to check our watches). Summer is hot in Europe, traffic is snarly, if you rent a car or rely on public transportation to get to where you are going, give yourself lots of extra time to get back to the ship, because the ship will definitely not wait if you go it alone. I have seen many a times a ship leave and people are running up the plank. Once it leaves, that is it, it don't turn back. Also, the way we see it, is if you can afford to get to Europe and get on that ship, why spend your time trying go check train schedules and worry about this and that. We also put money into our budget for tours. That is part of the cost. Instead of wasting it at the casino and drinking up a storm, we use that same cash for our tours - no hassle, air conditioned buses and just a great experience overall. Have a great holiday.