I have used this on my Harley Ultra touring bike and it is AWESOME!! It really makes the 600-750 mile travel days much easier on the butt.
One thing about it is the less air in it the better it works and forms to your rear end. Initially I had filled it about 3/4 of the way and it was to stiff. I called Danny Gray and they told me most people over inflate them initially. They said to keep letting a little bit of air out until I found the most comfy air pressure. Now it has 50% (or maybe a little less) of air volume in it and like I said above, it makes long travel days so much more pleasurable.
Would recommend, but it takes a while to get used to.
Overall I would highly recommend the Airhawk 2. It quadruples how long I'm able to comfortably ride.
However, it does take a while to get used to as it feels kind of like your floating on top of the bike. The cushion also seems to not stay perfectly in place, moving a bit as you adjust during your ride.
Make sure you don't over inflate it, as the instructions state.