Drupal's core architecture is extremely dated. You might like the hook system, but it is in no way a replacement for dependency injection a la Symfony2.

Urm, no. There's lots to like about Drupal, but clean code isn't one of theme. I mean, it's not PHPNuke, but clear and logical it ain't. I'm saying that as lead dev on a drupal site that pushes pretty heavy traffic and has thousands of man hours in it.

I love Drupal, but turning on devel.module and seeing 300+ queries on many pages was a bit of a fright.

^this. I actually grow as a programmer when I read through the Kohana source

If only they could get the docs back up to par! Things were sort of OK for 2.x, even if you needed some background in CodeIgniter to really understand everything, but half of the wiki for 3.x is empty pages with TODO's.

I still recommend that people new to Kohana start with 2.x because a framework is worth a lot less without quality documentation, when you have to go read the code all the time. Not that you shouldn't do that eventually, there's a lot of good code in there to learn from!

Because of the lack of documentation (v3), i begin to read source code to understand... At the and i found myself while writing my own framework :)

Really, Kohana needs more documentation....

Another developer introduced me to Yii when he got me on board for a PHP contract he needed help with. I was hesitant to take PHP work at first, because my previous experiences were harrowing at best. However, I found the framework was almost pleasant. It had a lot of the features I had grown used to in frameworks like Rails, and though I still have to wrestle with some frustrations of PHP, it is a minor annoyance as I go about writing good OOP MVC code.

I would personally pick another language if I were doing something from scratch, but the benefit is that it is a language others are already familiar with and so adding a framework like Yii isn't too hard.