You can look at this thread:
https://bitcointalk.org/index.php?topic=2605767.0
Many members posted their ideas hiw to improve quality of posts there.
I'm not complaining about Merit system, I think it's one of the best things happened to forum lately. I also liked idea to require payment to wear signature.  Now I think that Merit system are better solution than require payment to wear signature, but maybe both these things can be combined?
It would the most radical and the most effective solution.