Mollom module blocks non-spam content
I have used very successfully used honeypot and Mollom together with very positive effects.

I am not sure about lowering the sensitivity of Mollom however or improving its ability to recognise a quality post. I can only assume they have increase the strictness to ensure they maintain there high number of correctly classified ham messages.
for more information check out: https://mollom.com/blog/spam-vs-ham