What is the crowd's opinion of ContentTools?

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Their documentation is vanilla Javascript, not Coffeescript...
The source is written in Coffeescript, but transpiled into Javascript.

EDIT:
As for extending it, you don't really have to. There are hooks you can use to handle e.g file uploads and saving.

Thanks for the reply and the advice/links!

So basically I'll have 1 Symfony-installation where I develop my CMSBundle. In this first installation the BitBucket repo is set up in /src/CMSBundle and in the future projects I add the vcs-code to my composer.json file and it'll put my CMSBundle in /vendor/CMSBundle. (So basically my repo only contains the code from the CMSBundle-folder) Is that correct or am I missing something?

Also, I have used SonataAdminBundle and while it was pretty cool to use, I'd love to have my own CMS to build upon. I was planning to build a CMS back-end, accompanied by GeneratorBundle skeleton overrides and start from there, adding models and using the GeneratorBundle whenever I need new/edit/save/delete pages. Then for the 'pages' model i'd use Content Tools to enable the users to make basic changes in the front-end rather than the back-end.

Is that a good approach, you think?