Running an air shifter off is a lot easier than actually PKing them since most just fly away before they get near death, especially if their air form happens to be their most offensive. Air/Off you're not usually fighting the air form, just the offensive after they've done flyto peck or whatever.

You could take the fluid deceptions legacy (I imagine auto feinting every round is actually nice on certain builds, though probably not taken all that often as a legacy) to feint an attack every round possibly while using other commands, or do a double feint with the skill which can remove certain forms entire amount of possible attacks (i.e. Great white only gets 1 or 2).

My biggest problem with fighting air offense is that you have an offensive form with great ability to get the drop on you when you are not ready for them. Flyto murder is really only to seal a PK after the offensive form has trounced you to near death, and even then quaffing is a pretty easy counter, unless you're a rager in which case you're probably dead unless you're near a place you can evade the shifter.

Still, as annoying as air offense is, all things being equal there are generally much tougher things to try to deal with or avoid. Personally, I think skilled thieves, assassins or conjurers tend to be far more difficult to deal with than skilled air offense shifters.