It looks pretty. I just wish someone would build a decent CMS on top of silex/symfony/laravel, rather than implement their own framework to drive their CMS, such as in this case (Lime?!). I want all the extensibility of a fully tested framework but with some batteries included. Pagekit looks as though this could cover my needs.
Cockpit is about simplicity. I like it to be lightweight and with a minimum of overhead ... but I also understand you arguments. It's all a matter of taste :)
Even if there were an overhead, I'd rather have the stability of a fully tested framework than relying on an implementation with no tests.
What you have essentially done is created a framework, which in order for me to extend your CMS, I am going to have to learn. I also would lose the added benefit of not being able to use existing packages for (insert widely used fw here).
I can't really understand why you aren't using composer as well, it seems as though you are managing your own dependencies in the vendor/ folder?
Look, I have respect for you going out and creating your own cms. But I seem to get constantly disappointed when I dig into the nuts and bolts, and unfortunately this one is no different.