I am familiar with both Zend and Symfony framework for PHP. But I could not say which is better. They are good in their own ways. In Symfony, propel as ORM and it builds. But in Zend instead of propel, uses the classes provided by the framework. A good thing for Symfony developer is that there are many tutorials available for Symfony in web and also the forums are very active. It is very easy to get solution for a question in Symfony from web. Zend has a very good reference document in their website, but support from outside is very low.
Here are some of the useful technical documents that I found during my works