The reason I'm doing the conversion is because of the lift. I'm running about 5" right now and proably more like 6" by the end of the summer. A u-joint will help with the driveline angle and the rotoflex can get damaged on the trail more easily that a u-joint propshaft.
Other than that, no real reason. Most Discos, even with 2-3" lifts go their whole lives with the rubber donut on their rear ends and live long, happy lives
