Zend Framework Performance - specifically helper vs partial vs action helper vs action stack

There is a good section in the ZF reference guide regarding performance.  Specifically, pertaining to helpers, partials, action helpers, and action stacks.  This article hates on the partial because it is expensive to clone the view object.

http://framework.zend.com/manual/en/performance.view.html
http://framework.zend.com/manual/en/