We loved Giovanni, he was everything you would want in your driver! Easy to understand, had a headset mike so everyone could hear him, and was wonderful and informative. Kept everyone entertained from the 75 yr old grandparents to my 13 yr old son. Pompeii was great, we hired the private guide and Giovanna, and she was fabulous as well. Now you can learn from my mistakes:
1. Giovanni will give you the option of trying to see Sorrento and Positano, or do one town and have a nice lunch. We opted to try and see both towns which even in May was ridiculous with the terrible traffic. Pick your favorite and have a nice lunch or you will spend too much time in traffic and get very little time in the towns.
2. I have read about Giovanni taking someone to a ceramic factory and didn't buy any ceramics in the towns waiting for the factory! Huge mistake and lifelong regret. The factory is really only for big pieces like tables and chairs, BUY WHEN YOU HAVE THE CHANCE! I cried when we got back on the ship.
Otherwise, have a fabulous day trip!