Unlike Puerto Misahualli, which has a certain charm as a holiday village, Coca is a town spoiled by the oil industry, the airport, traffic and deforestation etc. It is, however, an obligatory stopping point for tourists visiting the Amazon. Most people stay just one night before heading off to their lodge in a dugout canoe or on their trip into the Amazon rainforest.
I went to Coca on my way the Cuyabeno Wildlife Reserve, to the north. You also have to go via Coca to visit the Yasuni National Park, to the south. These are two beautiful places where you can see animals in their natural environment.
The town of Coca doesn't offer anything in particular to make it worth staying there but the surrounding area is really very nice. Make sure that you book with a travel agent that puts income from tourism back into the indigenous communities.