Dunno?
I thought my sheepskin was great, waterproof, comfy and a great talking point wherever you went as it looks so different! Used an Airhawk last year for our big trip, as previous poster said, takes a bit off getting used too, can move about under braking etc, just have a squishy feeling under your arse all the time!!
We are off to Constanta, Romania in two weeks and to be honest I dont know which one to use, both have there merits, if you have some spare dosh then buy one, if not then dont worry and stick with woolly!
Sorry not to have a definitive answer for you!
Cheers.