I'm not the poster but the last time I looked into Cake it's internal code was just an utter mess. A lot of the mess is from it's continued support of PHP4 and PHP5 which have a lot of incompatibilities in their object models.
I haven't used Symphony in ages, but it was originally a fork of a project called Mojavi (which I used to work on). It was designed as a pure PHP5 MVC framework with a heavy emphasis on being easy to override or modify any of the components. I don't know how true it's held to that these days, but the original code base was pretty slick.
That said. I don't use either, I've got a little 300 line OOP MVC wrapper I wrote that serves my purposes. But if I were going to look at a framework today it would be Zend or Symphony.
CakePHP has changed ALOT, and for the better to boot! As a 6 year php coder and a 2 year cakephp developper, I HIGHLY recommend it.
Yes, everyone thinks the docs aren't good. They're currently pretty decent actually. Also, the community is amazing and all of it (core code, docs and community) is just getting better.
It's a really good, VERY flexible framework and most important; incredibly portable, which I think is the reason why I love it.. I haven't had a hiccup with it since the latest versions have come out (1.2 RC3?). I've also done ALOT of client work using it, rarely on my on web host. It is the Madlib to rails' Timbaland.
That being said, cakephp 1.1 was REALLY bad. I can't stress that enough. This is probably why it gets so much bad press. There's still ALOT of information written on 1.1, alot of technical articles, howtos, etc.. and an upsetting amount of reviews and performance tests based on 1.1 or early beta 1.2 releases.
I capitalize ALOT. I'm REALLY sorry. I just really like cake...
The debug bar in symfony is a big help to understanding what your application is doing and which bits of it are running slowly.
The symfony model layer is also much nicer. Cake's models are thin, making it difficult to place much logic in the model and to reuse and extend model methods. Symfony uses propel which has an excellent way of passing criteria for a db request around, making extension easier and reducing code repetition.
The symfony askeet/jobeet tutorials are well worth working through, they do a great job of showing you how to build an app.
Since first trying symfony I've found myself replicating its features and style in other php frameworks. For example I'm currently looking at if I can insert the Propel ORM used in symfony into cake to replace its model layer.
