I had a discussion yesterday with my new coordinator in regards to frameworks. I told him that I was working on my own framework/code base for which to base all future projects off. His argument was that it would be better to go with one of the many free PHP frameworks available like Zend, CakePHP, etc, as they've already been thoroughly tested and have well established support communities. All of which is valid, but Frameworks to me have always seemed like massive bloat, and possibly an amateurs tool. So, I've once again come to the sitepoint forums seeking wisdom.
What are your thoughts on using a PHP framework for development of web applications (on an intranet) and public facing websites? And on what scale does a project have to be for a framework to become useful/time saving/etc?