Constitutions as Living Documents?

People sometimes refer to a constitution as a living document. In the United States this is only somewhat true. We have had the same constitution for 200 years and the amendments are the only parts that have changed over the two centuries. However, Latin America has a history of changing constitutions often. During the post-colonial era liberal governments would write a constitution and then it would be overturned in favor of a different type of constitution. It seems like Colombia created a new constitution almost every ten years during this period. This trend has died down somewhat in current times but at the end of September Ecuador ratified a new constitution. I am not sure if their are any benefits to the constant changing or if it is better to have a more permanent document in place, probably the second one because it offers more stability.