Finally put on the 12 tooth sprocket last night and went for a test spin. Seems real nice so far. Went up a cpl twisty hillclimbs that I would start to bog on in 2nd and had some powerband this time. I was a little surprised how much it geared down 3rd, and especially 4th and 5th. It almost seemed to have more of an effect here than on the low end. But, I need to ride it more still to really get a feel for it.