airbags do seem to be more common in the euro zone, we have them indoors in the UK and at my local hill here in france. There good fun, the only time i've ever seem anyone really get hurt is when they didnt carry enough speed off the kicker to actually make the bag. They just fell of the backside of the kicker
My biggest problem with them is they tend the make the kicers narrow which makes spinning more difficult and they are artificially steep compared to 90% of park kickers as they dont want you travelling a distance. They just dont mimic most real life kickers very well.
I've never really learned very much off them