The air gap seems a little too gimmickey for me. Sure, I know all the theory of cooler runners etc., but I think we are talking small fractions of HP for some extra cost. Also, as I recall the ones I have seen have pretty rough mold marks under the runners.
They remind me of baseball gloves (wow, where did THAT connection cme from?!?). Think about it. If you are a baseball fan and look at the new gloves at the sports stores every year like me, there are always a bunch of PATENTED new finger straps, lacing patterns, web designs, etc., etc. Still comes down to whether you can get yourself in a position under the fly ball and put the mitt between your face and the ball to a) make the catch and b) protect your nose!
In hot rodding, I would spend my time and money building a good engine/car and if I had a little left over, get a gimmick like the air gap.
[ March 03, 2003: Message edited by: email@example.com ]</p>