We've done the Medit. cruise thingy 4X in 3 years - simply because there is just so darn much to see and do and the ships are in port for such a short period of time....we just keep going back again to pick up things we missed the time before.....
Last August we booked Millie for May 12 Medit. cruise - but Celebrity cancelled that itinerary following 9/11. We never rebooked and did Hawaii instead.
On our Medit. cruises we have done a combination of things - on the very first cruise, we did all ship's excursions and that provided us with a basic knowledge of the areas so that on future cruises, we were fairly confident in our ability to strike out on our own. One of our best experiences was "jumping ship" in Naples last year.
One suggestion for you - Second seating in the dining room we found to be a must due to the amount of time it takes to get to some of the destinations and back to the ship, i.e., Rome and Florence. We found that the late seating provided us with time to really relax upon returning to the ship from a full day of sightseeing before we started dressing for dinner.
One more suggestion: YOU'LL NEED A VACATION WHEN YOU RETURN FROM THIS FANTASTIC CRUISE!
Enjoy your Medit. cruise.