Instead of spending three days at Bocas del Toro, I have decided to spend my time taking the longer, but (according to my guide book) more scenic way via Turrialba to San José. I also took the opportunity to break the trip there and visit some nearby Indian ruins.
Now I know that my guide book was right: The mountains around Turrialba are indeed quite scenic, even in cloudy weather. Moreover, also the Indian site was quite interesting. However, even though it is the best one in Costa Rica, it cannot compete with the temples found in Mexico or Guatemala. Still, all in all, Turrialba was a worthy replacement for Bocas del Toro.
By the way, looking for a hotel room in Turrialba was also a quite interesting experience. I went to a hotel listed in my guidebook, where I was told that a room costs 6000,– Colones. When I wanted to pay, and the owner found out that I would not be leaving until nine or ten o'clock the following day, I was suddenly told: "Well, if you want to stay until tomorrow, the price is 8000,– Colones!" After being a bit dumbfounded for a couple of seconds, I quickly grabbed my cash and my backpack, and left for another hotel, where I now pay 9000,– Colones per night. However, I still cannot believe that my guidebook actually mentions a hotel that rents rooms by the hour!