Amalfi coast - boat or a ferry?

We are a family of 12 (incudes 2 seniors, 5 kids), planning a visit to the Amalfi coast (Positano, Amalfi) from Sorrento in the 2nd week of May. There is a huge price difference between hiring a private boat, vs hiring a ferry so our obvious choice is the ferry. But are the views seen from boat very different from what we’d see if we take the ferry?

Also, if we take the bus on the way back from Amalfi to Sorrento, is there a way we can book seats on the bus to guarantee good seats by the window?