I use Sass with postprocessors. They are not enemies. Sass and preprocessors are better to fix CSS syntax. Postprocessors are better for some automatically task, like autoprefixing, media queries packing, polyfills, etc.

Unfortunately, Sass is not so flexible as JS. Even simple things require a lot of code. And a lot of task is just impossible on Sass (for example, Autoprefixer, RTLCSS).