I use LESS to at least define constants easily. It's useful to be able to define your site colors as a few constants to keep things consistent. Theoretically, I

I use LESS to at least define constants easily. It's useful to be able to define your site colors as a few constants to keep things consistent. Theoretically, I could dynamically generate it on the server for the same effect, but that breaks my workflow because I usually write the HTML + CSS first in a prototype page before writing any server-side code. You can mitigate #4 and #5 by importing less.js during development. I don't know if SASS has something similar.