PHP Framework: CodeIgniter vs Kohanna vs CakePHP?

[eluser]Phil Sturgeon[/eluser]
Let's assume you know PHP but nothing about the frameworks, the strongest point here will be documentation.

CodeIgniter has a LOT of documentation which is of much better quality than CakePHP's documentation. Kohana basically has none.

If you'll be building a massive app you will need to know how and how quickly, CodeIgniter is the best way to do that. It is also flexible enough for you to do whatever the heck you like without it bossing you into certain conventions - something that CakePHP is full of.