My wife and I just left and had a wonderful time!
For Capri, we did the Mondo Tours Rick Steves boat special which was 9 hours for 80 euro (per person) which is worth the splurge. We saw the Blue Grotto, Green Grotto, White Gratto, and Coral Grotto. We swam in the Mediterranean, which was cold but amazing. Plus we got 4 hours to tour the island (the views from the top are amazing!). They even pick you up from your hotel and provide lunch and a beer.
Positano is amazing and the Sita bus was fun (we did not have to wait long) we got on at Sorrento (we really liked Sorrento).
The trip from Amalfi (town) to Ravello was great, but we waited forever for the Sita bus - consider taking the pink bus (I think it is city tours) to go up. The views are amazing.
Other than the Cathedral, There isn't much to do in Amalfi. We agreed we could have skipped it (the hotel Floridiana was great, though!).
We went to Paestum and it was amazing. A little bit of a haul, but if you like Roman and Greek history, you've got to see it! The Roman ruins don't get much of a highlight, but you are free to explore pretty much anywhere and we were finding neat pieces of history, like the mosaic floors and parts of the original outer wall coverings.
We loved Positano! We had a great day trip there from Sorrento. Relaxed on the beach and people watched.
Have a great trip!