I think there is a general misunderstanding about when these tools should be used, and how they can benefit your site overall. The issue for most people is that once they have optimized their CSS, it is completely unreadable and impossible to update. Optimizing the local development copy of your CSS isn’t really the right way to use the tool.
The idea of CSS Tweak is to provide optimization for deployment. So, this means you would keep a development copy of all your CSS files on your local machine. Then, when you are ready to upload your site, run the CSS through CSS Tweak, and upload the optimized files. This way, you have a perfectly maintainable copy on your own machine, and an identical copy on the server, only fully optimized, reducing your site load times and bandwidth usage.
That’s all really, I just thought I’d talk about this briefly, as it seems to be a recurring question. I don’t think I made this all that clear when I first released CSS Tweak, so really it’s my own fault! Has anyone been using CSS Tweak in this fashion already?