I finally got some miles on my YJ both on and off road and I'm feeling pretty good about the inertia ring. Off road is where I was hoping for some difference and I believe it helps a lot. I can creep much easier up hills an over obstacles with a lot less clutch feathering. As far as wear on the clutch I think there will be a lot less abuses on it when 4wheeling. This isn't a DD even though I've been driving it more lately because it's fun. Since this is a new rebuilt engine it has more power than my old tired engine with 170K miles. I did the 4.0 throttle body up grade and really can't say that made any difference either. So what effects it has on the road, I can't say for sure. It may take a little more time to slow down when you take your foot off the throttle. There is more mass in motion. And I do feel and hear a little more vibrations but then I also installed polyurethane Brown Dog motor mounts and brackets. So I can't say that the inertia ring caused the extra vibration. When the engine was in out I ran a dial indicator on the ring and it had less the .030 axial run out and under .010 radial. The flywheel itself had almost .040 axial. I'm planning on swapping for the rubber motor mounts sometime soon so we'll see what happens with the vibrations then. Old Jeeps have vibration and rattles anyway.
So overall I'm glad I installed the ring. The slow creeping torque it has is pretty cool.
Craig