Looking for opinions again

I am considering putting my truck on the rolling-loaded dyno at Granatelli Motor Sports in Oxnard, CA for testing and tuning. After speaking with the dyno techs there it seems my application would be fairly straight forward to diagnose and not too expensive, between $500-600, for a session that would include:
-dyno testing for base HP and Torque to the rear wheels
-setup of my dist on distributor machine, set optimum advance curve
-gross tuning of carb for optimum air/fuel mixture at quarter, half and WOT
-re-testing and fine tuning
-final dyno testing with output showing HP and Torque across the RPM range and % of improvement

All in all they will do several pulls and all bench service required to get there.

In my opinion a service like this is invaluable and an obvious WHY NOT, just wondering what you guys think and whether it is worth upwards of $500