A scooter is definitely your best option because taxis are very expensive and Buses are very slow.
The downtown area of Puerto Vallarta is quite long and narrow, meaning it could take an hour or more to walk from one end to the other. If you are looking to move around the city or return to your hotel, definitely on board a Scooter it will be the fastest and most fun way to get to know, the great advantage is that you can park anywhere.
Also to get to know the beautiful towns that surround the bay such as:
• Nuevo Vallarta 20 minutes by motorcycle
• Buceras 35 minutes by motorcycle.
• La Cruz de Huanacaxtle 40 minutes by motorcycle.
• Punta de Mita 50 minutes by motorcycle.
• Sayulita 50 minutes by motorcycle.
• San Pancho 60 minutes by motorcycle.