IMO, it's a nice toy, but for 99% of trail time, it's more of a PITA than anything. I've wheeled with a few guys who had it, and they didn't run as smoothly thru the trails as I did (yes, partly since they were new to rear steer, but IMO, it wasn't enuf help for the price)
Obviously, portals or D60's required, I'd never consider it on stock Cruiser axles.
There is one REALLY nice setup for rear steer that allows all your input to come from the steering wheel...cruiserrg is planning on it for his Mog-axled buggy, but the steering alone is $2500....best be winnin' some comps for that investment!