The guy at AZ Dyno Chip (ADC),
http://www.arizonadynochip.com/ , knows his stuff. It's a Dynojet, so inertia type dyno, but he really does knows how to work the thing and tune. Probably shouldn't be tuning on a dyno day though. He'll produce graphs corrected to SAE value with zero smoothing, so they're realistic. We had a dyno day a while back at AZ Dyno Chip (ADC) It went really smooth, efficient and was really fun. The dyno day we had at Arizona Dyno Chip had the guy that runs the place making dogs, burgers and chips with pop. He's really a great guy, quiet and modest, but you can see his brain working while he works the dyno. He loves Fords too.
http://www.arizonadynochip.com/rates.php
Dynojets, when used correctly, are going to come out very close to HP calculated from trap speed of 1/4 mile. Definitely the most fun for a dyno day.