We had 3 glorious weeks in the area in June with 2 nights each in Ravello, Praiano and Positano, plus 4 nights in Sorrento.
Umberto Limos Positano was great: punctual, new vehicles, assertive but not crazy drivers.
When I go back I would do 3 nights each in Ravello and Positano. Ravello is an idyllic haven with terrific hiking paths going up and connecting to Amalfi, and going down to Minori, etc. La Dolce Vita offers reasonable lodgings for four with great views.
Positano, despite the crowds, was enchanting, especially staying overnight. Villa Rosa has amazing terraces and is the among the most reasonable in Positano. It has a ferry port to get to Amalfi or Capri.
Sorrento is larger with many more hotel options and makes for a nice transportation hub. I wouldn't stay so long here unless you plan to do Pompeii or Vesuvius or Naples from here as well.
Some maybe: 2 nights Ravello; 3 nights Positano (ferry to Amalfi); 3 nights Sorrento (ferry to Capri; maybe also to Ischia).
Enjoy!