Very hot and crowded this time of year. We took the hour plus train ride from the port in the morning and it was packed. The Metro in Rome made it easy to get around town. We visited the Forum and the Colosseum and headed back to the ship after lunch.
It is incredibly hot and crowded around the Acropolis. Be sure to wear good shoes as the marble surface is quite slippery. The ship tour stopped at a crummy gift shop of course; no more ship tours for me from now on. The saving grace of the tour is that the Acropolis is truly spectacular.
The half day drive around the island in the jeep was more like a scenic tour of road construction. The stops (a decent beach, Popeye Village, a scenic stop) were mediocre and I found the drive to be quite hot and boring. The driver was nice enough and he dropped us off near town rather then back at the port; otherwise I considered this tour a complete bust.