It's discussed in this thread and many others. The TL;DR is that nobody knows what the 'best' setup is. My vote is to adjust it so that the fingers don't leave the TOB, but instead rest on it with minimal pressure. This is difficult to setup and measure, though, and too much pressure could cause all kinds of problems. Most people adjust it to pull off of the TOB completely.
I'm noise free with 7k miles on the setup described in the link - 10k total miles on the TOB.