I'm at the very start of a longtime running project with continual development. Because of that I'm hoping to make a good decision in which Framework will be right for this.
Previously I've worked with Codeigniter. A plusside is the huge community with a great User Guide. A few of the downsides are the backwards compatibility with PHP4 which holds it back and (therefor) the lack of OOP.
Because of that, I'm considering the use of a Framework like Kohana or Yii. I'm writing 'considering' because I'm not sure that the User Guide, Documentation is sufficient for us.
My question is not to start a blog-like upside / downside comparison. My question is whether or not you have experienced drawbacks from a more or less imcomplete User Guide, Documentation like Kohana or Yii.