Question: I am deciding on a framework to try out for PHP. I have narrowed it down to CakePHP and CodeIgniter. I have a couple of questions for any of you who have used or are familiar with both:

1. I like the fact that CakePHP keeps most of the code outside of the webroot by default. Especially since I may end up using a single framework install for multiple apps. I see CodeIgniter will do that too, but you have to configure it and move some stuff around. Is that workaround secure and reliable, or is it an afterthought hack?
2. Which (if not both) is easier to upgrade, and maintain over the long term? As new versions of the framework (and PHP itself) come out. I don't want to find my stuff either breaking, or becoming outdated.

**Edit:**

This is a very old post, but I thought I would update it with what I finally ended up doing, which was to use Kohana.

Answer: 
You should **try** both frameworks for a week or so, building something trivial (like a blog or wiki) in both, and see which you prefer using. Whatever makes the most sense *to you* will probably sustain you the longest through upgrades an deprecations.

CakePHP is in a bit of a volatile state right now, still unearthing bugs while pushing to release version 1.2 (which is not backward compatible). I wouldn't suggest building a critical application with it if you need something rock solid *right now*. If you can wait a month or two for things to settle, then it's probably a moot point.

To address your concerns:

1) Cake and CI do it the same way (iirc). They are equally secure, reliable, and hackish on this front.

2) Everything changes. If you need concrete, perpetual assurance of stability and backward compatibility, roll your own framework. There's not that much to it, and you're guaranteed that nothing changes unless you want it to.
1. is a non-issue.
2. CodeIgniter has a sponsor behind it, so it's definately the one to choose for the long term. Also, it's faster.