What are some drawbacks/benefits of using ctools? What is the purpose of ctools?

Are there any drawbacks in using ctools for one's programming needs?
Also, what are some benefits to using ctools? From the project page it seems to just be a large collection of random tools.
Discovered the best place to learn this is actually from a lecture from drupalcamp austin in 2010 by Erik Summerfield.

http://vimeo.com/17957123

That's just a start. Otherwise going through example ctools integrated modules has helped as well. The fact is (at this moment) documented use case examples are limited.