Most banks in Puerto Vallarta are open Monday through Friday from 9am to 4 or 5pm, and from 9am to 2pm on Saturday. Closed on Sunday. They are notorious for lineups.
Banks give a minimally better rate of exchange over casa de cambios, (money exchange booths), but you may have to wait in line. Changing money at a casa de cambio is quick and they have later hours than the banks.
Unless you are exchanging a large amount of money, a money exchange booth (casa de cambio) may be more convenient and less time consuming.
The best rate, however, is usually the nearest ATM and they are open 24 hours but do have a maximum daily withdrawal.
All the major supermarkets, and a growing list of other merchants, are accepting purchases made with a Mexican debit card with your signature. And of course most places accept MasterCard or Visa, but will usually pass the credit card fee of 5 to 6% on to you.
Casa de Cambio's