rock krawler lift

anybody have a "rock krawler" lift...i have been looking at the long arm rock krawler lifts and they seem to be very good and they have a very reasonable price so i was just wondering if anybody has had any experience with one...and a couple more questions...with a 5.5" lift how much chance of rolling (flipping) is there (on the road)...and is 1400+ rti ramp score on a 20 degree ramp good?..thanks