When you consider that the average person on this site has at least $5k worth of extras on his ride, and that most of those extras are of the chrome variety, the under $400 cost of this item is an incredible bargain. Once you've ridden a full size Harley rubber mount with one of these units on it, you are never again comfortable with the feel of one without it. Road Glide, ELectra Glide and Road King are all the same vehicle if you strip off the sheet metal and fiberglass. The chassis are identical in every way except perhaps for the gear ratios of the transmission on some models. I think the reason behind what 103 has pointed out is the way the different fairing and windshield configurations react. There are big differences in the handling of these three models. Still at the end of the day, the rear wheels react the same. At speed, they tend to oscilate around corners vice carving them. The True Track will make all of them carve a corner much like a sport bike-- - - - - - as much as an 800 lb motorcycle can.