I have used Airhawk cushions for a while now. My job consisted of being on a motorbike (usually my TTR250) for up to 12 hours a day. Imo the Airhawk not only saves your arse but also your back, as it absorbs a lot of the short, sharp jarring movements so prevalent in off-road motorcycling. If you are a time/distance rider, you just can't go wrong. Btw, I always use the straps, otherwise the cushion will fly off when you are standing up. Using an Airhawk, you will eventually get uncomfortable, but it is nothing like going without. And I don't have any shares in 'Airhawk', either!!

I use the small cruiser one, which may have been superseded by now; not sure.