Recently Jon Cohrs finished mastering two new records of mine, Subatomic Particle Homesick Blues and Unfold Ordinary Mind. This brings to five the number of projects that Jon and I have worked on together -- two cd's by Tin Hat, a recording of mine called Go Home, and the two records mentioned above. So I speak from experience when I say that Jon Cohrs is one of the great mastering engineers alive today.
In other words, I give Jon my highest recommendation -- I know I will not work with anyone else.