If you can afford it take a private tour. Our driver was Francesco and he was fabulous. He took us on a tour of the Amalfi Coast and Pompeii. You will learn so much and he will do whatever you want to do. Totally customized. Then you can go back to the places you want to spend longer time on your own. He hooked us up with his friend Sasha for the Pompeii private tour. Sasha's father was a guide there for 45 years and as a boy Sasha and his buddies used to play all over Pompeii after school. He was amazing and the depth of his knowledge is something you could never get on your own. It was a highlight.