Unless you pay for the more extravagant excursions, most coastal Mexican towns/ports are very similar with a lot of souvenir shops and pushy junk vendors.
In Puerta Vallarta, the Cathedral of Our Lady of Guadalupe is a must see.
In Mazatlan, the open air buses were down, so there was no affordable way to see the city.
Clean, but a little cramped. Bathroom is tiny. Balcony was great and private.