Fast answer
Trulli and countryside stays make Valle d'Itria feel distinct, but they are not a universal upgrade. Choose them when the car is accepted, dinner logistics are clear, and the lodging experience matters as much as town walkability. Alberobello should be planned as a major trulli stop when it is included, while masserie and contrade need property-level checks for access, meals, parking, late arrivals, and returns.
If you only do one thing
Choose a trullo or masseria only when the trip is comfortable with daily drives and planned evenings. If travelers want to walk out every night, a white-town or Martina Franca base is usually cleaner.