Elba, Capri or other
 

Looking for an island experience for about a week in April-May. Don't want to go below Naples. What's been your experience? Apartments to rent? Moderate/easy hiking/walking? Other activities?

You don't mention a price range, but finding a rental in Capri is going to cost some good money. Besides Elba (or Corsica for that matter) Ischia would probably be a better chance for an extended stay both in price and in the number of activities.