Hi Ben, I have not paddled either board, but the Airline has always rated well in the tests and reviews I have watched.
If you want the stiffest board the Naish Maliko will be worth a look, here is a link to a SUPboarder review which might help.
-eAKcC
I just brought a carbon Maliko and looking around for reviews on Youtube did not find much, then a whole bunch of race videos from Japan popped up. Just about every type of hard/inflatable SUP being paddled, you can get a great idea about the boards by watching how they handle the different riders and sea state.
Hope that helps.
Steve.