[Read] Why Choose Pyramid

http://www.quora.com/Is-pyramid-is-better-than-turbogears-2
Pyramid is a low-level framework, like Pylons.
The design goals of Pyramid are to provided just a little infrastructure and let the developer decide what s/he wants to actually use.

http://www.quora.com/How-do-Rails-vs-Flask-vs-Pyramids-compare-as-web-frameworks
Using a lot of tools that are not traditionally used with Django, i.e. MongoDB. Django to be too tightly coupled.
Flask: simple and clean. Doubt whether there are enough plugins at the moment. Don't know whether Flask will get big in the future.
Pyramid: Bigger than Flask, smaller than Django. New, fresh, quite stable and widely used in industry.
Raild: The language is not as clean as python. Huge community and lots of plugins. There are some problem like scale.

http://www.quora.com/What-kind-of-web-applications-does-Pyramid-specialize-in
Pyramid does not 'specialize' on a specific kind of web application. Pyramid is much more loosely coupled. One of the most visible demonstrations of this is that Pyramid doesn't come with an Object-Relation-Mapper or data access layer by default.
Pyramid is also more low-level framework compared with Django. It does less out of the bow, and assumes you'll write more functionality yourself, or plug in other libraries to help you.

http://www.quora.com/How-difficult-is-the-Pyramid-framework
The author is able to setup his first Pyramid application in three hours.

http://blog.fruiapps.com/2012/05/Choose-your-Python-Web-Framework-the-Hard-Way