I have them in my 08 FLHX. It was installed by the previous owner so I have not been on a bagger with the stock rear shocks. I love the fact you can adjust the ride as well as the height. My chrome is peeling off though. They are 4 years old with only 7,000 miles on them so the finish is a big let down.
I have it on my '09 Ultra and love it I am short 5'6" with sort legs that are very muscular so I have thunder thighs and with the Arnott air system I can drop 3 inches out of my bike in about 3 seconds, and like said above I like that I can adjust the ride for whatever road or load I am in.
Hi from the UK and welcome to HDF. If you use the 'search' facility (centre of the blue bar above) and enter 'arnott' you will find plenty of threads to keep you busy. Get a long drink first!