I have one and it is very versatile. They recommend that you put very little air in it. I tried it that way and it worked. Then I figured out that if I turned it backwards, it would support my thighs better that just a stock seat. Then I used it backwards on my Diamond seat and it even helps there. Now I have filled it with as much air as possible and use it backwards. Seems to fit right between the cheeks and spead out the pressure points. Have not ridden all day yet, but it seems very comfortable. Completely filled, it raises me another inch. Filled per instructions, the difference is imperceptible. Best price I've found is here.
Yes I think it's worth it and it has held up well, I've had mine almost four years now. It does raise you up a bit and circulates air under your butt. It took a little getting use too, I use it everytime I ride.
I have had the AirHawk for about a year. Being slight on the backside is my main problem, plus I am 6'4". The support given is great, it has cured the numb butt. I used to only be able to ride about 100 miles before getting numb. My longest trip with the AirHawk has been 425 miles in one day----NO PROBLEM! It does raise you sitting position slighty (remember to NOT blow it all the way up..follow instructions that came with it).. but I have a Tulsa windsheild, so it's not a big deal. The extra room for the legs was minimal, I don't think you would go wrong with this purchase.
As you have probably figured out from the above posts, I do not always follow instructions, many times to my benefit. This is one of those times. I just finished a two hour ride on my Airhawk, fully inflated [contrary to instructions] and using it backwards until the last 10 miles. I find that so far, I prefer it this way. [Don't know yet if I want it backwards or frontwards, but that will come.] Now I have no idea how this will affect the longevity of the Airhawk, but I am well aware of how it will affect the longevity of my butt. And I pick, er... choose my butt. I obviously don't know if anyone else would prefer it this way, but this is my experience and I'm stickin' to it. JMTCW.
For general riding, I don't use it, but on long rides, hell yes!
Two rides come to mind that I could not have done comfortably. One was my SS1000 Iron Butt. I'd hate to think of that without the Airhawk.
The other was simply a business trip where I took my bike instead of a car. 750 miles over two days and though I had had enough of riding and dealing with traffic, the airhawk was pleasure to have a long. Sometimes I'd put it back in the trunk for a different break, but it will always be my long distance companion.