The Marbella area of Panama City has lots of commerce.. as the banking area is nearby. Few residents and visitors there use public transportation. It has lots of traffic. Its closnes to the Panamá Bay and high buildings make this place very interesting. Because it has many amenities and facilities in the surrounding area, a visitor actually doesn´t need a car if the business he is doing is in Marbella. There are hotels, hospitals, malls, the World Trade Center, restaurants and little shops all over the place.
But if you plan to move around the city and you are not familiar with the area, is best that you take a hotel cab as this will help to do your errands quickly and accurately.
I would say that you would lose valuable time waiting for public buses, even though they are very modern and clean, and cost is only $0.25, but again, you need a card purchased in advance, and that could create a problem for the visitor who doesn´t know where to purchase it.
Buses run from main avenues, and all of them go to the main terminal in Albrook, where there is a mall, as well, and an airport very close by. Sometimes, when they´re very crowded, especially in peak hours, people don't get seats, and have to go standing up, so it´s not very pleasant. To take the bus, sometimes you have to wait in long lines.
Small yellow taxis are a good alternative, but again, some of them don't follow the regulations, and could charge more than the official fee, or just say "no voy" (meaning "I don´t go there"), as well as some of them drive too fast, or take secondary roads, trying to avoid the traffic jams, which is not convenient for visitors, who are only seeking enjoying the city, or going to an office for business. Another issue with yellow taxis are that customarily, a taxi usually takes more than one passenger, if doing so allows the taxi driver to goes basically on the same route, and is admissible. In addition, there an be others in the taxi with a noisy radio or the air conditioning may not work, or the car may not in great condition. It depends on your discretion if you accept a particular taxi, or not. Of course, there are also hundreds of them that meet the requirements.
As in any other place, if the driver sees that you are a tourist, he might charge little bit more, not that is correct, but it happens sometimes. A standard fee from point to point within the city could be between $1.50 and $5.00, depending how many zones you cross, how many people are in the cab, or if you have many packages.
The best place to take a bus in Marbella is Calle 50, or Avenida Balboa, depending on where you are staying.