I have been running them at about 35psi which seems a little hard already. I dropped it to 30 in the front once and the tire burped and I crashed. The traction and confort was good but Im a little scared to try that low of a pressure again.
Like you've mentioned, it's a "feel" or personal preference and riding style thing. If you are light on the pedal you let your tire pressure do the work of conforming to the terrain, then the low pressure would be right. Most set up would feel pretty hard especially Maxxis UST with stiff sidewall. I used to ride with this set up.
However my riding style change, I'm more aggressive and heavy on the pedals. I find that higher psi provide better feel and traction suited for the riding style. I'm no longer have to worry about burping air in the corners or g-out sections.
I find that I have more traction with this set up as I can load my tires more aggressively, yet even with higher psi there's plenty of forgiveness on the tires on both ends. I'm running 28/30 f/r on a 2.35 full knobbies.