So tasked with updating an existing PHP app I chose to use the very powerful and often under rated Yii Framework. Let me say for the record, it has been an absolute pleasure to develop with and its blazing fast. Sure there are some nuances to learn, like all the config items are in arrays, but thats not different from other frameworks except that with Yii there are so many options it can get tricky to maintain.
But you really deal with config array for very short periods of time and then you move onto building your app. I found GII the GUI based code generator to be extremely powerful and it has done like 80% of the heavy lifting for me. I generate for example all the CRUD code I need and then I change and re-structure as I see fit. In addition to that the performance is stellar.
Certainly checkout this awesome framework, especially if you want to get things done very quickly or you need to prototype an app.
Better still if you need an app done quickly drop me a note.