hello david....i use air dried baits.i didn't find any change in catch rate when i switched from frozens,they are both equally as good as each other.
the only real pitfalls with air drying are;
storage...beware of using plastic bags,they get condensation in,and your baits will go mouldy,many people,myself included,have fallen foul of this one!...mesh bags or hessian type sacks are ideal,anything that lets air in.
size and weight....once all the moisture is out of the baits,they lose a lot of weight and shrink,if you need to bait up at any kind of range,you could struggle.
hardness.....not for the fish to cope with!,for your poor boily needle,you will need a nutdrill to get your baits on the hair.
apart from those 3 minor things,they are superb,and not having to use the freezer for your bait is a major plus.i've used air dried baits up to 2 years old,and caught no problems,i reckon they will last indefinitely.
make the jump and use them with confidence david,i'm sure you'll have no problems
regards mark