Reason 1:Fit. Rancho had the correct size for my application.
Reason2: Adjustability. After installing my lift I noticed the front end severly "Nose-Diving" while hard braking, which was unacceptable to me if not unsafe. The adjustable Rancho 9000's allowed me to stiffen up the front to stop the "Diving" and leave the rear a little softer for some comfort. After adjustments were set, I havn't touched them in years.