Tired of this?

Or this

Or even this

There is solution for you — cf comment filter. Download this google chrome extension and enjoy clear codeforces.

Details: install extension using this guide. Choose color in popup menu, and you won't see comments by users with rating strictly lower than this color (If there is some answer by high-rated user it won't be hidden).

Maybe I'll do some of following features in future: firefox add-on, customizable list of blocked users, hide blogs (doubt this one).