Good and Excellent proc's for me tend to be very high. Of course 75% of them are shoe horned in to derail my rotation. I don't know if that's true at 60 2 star or not but I'm sure it is. Comfort zone, Inner Quiet, Steady Hand II, Waste Not. It's locked in to the rotation and more often than not, the goods will show up there. The amount of good conditions I get between SH II and Waste Not is insane and I'm sure it's the same for everyone else.
It would be interesting, though very difficult to conclude how many proc's come out, compared to how many come out usable.