The AC's steering geometory is such that it suffers from alot of bump steer. IE if you hit a good size rut or log with only 1 tire there is a good possibility that the handlebars will be riped out of your hands. Sprain wrist or worse can happen pretty easily. What it does is resist quick movements of the handlebars. Same as a steering stabalizer on your car or truck.
Lot's of discussion on the Outlander800.com forum about the stabilizer from Precision. The few guys that have them are very excited about them. Much easier to ride and ruts don't wear you down after a day's riding. Pricey though at $500. Don't know if they make one for the Cat.