Took my S4 here for checking out on the Dyno:
http://www.swintonmotorcycles.co.uk
Top place and not expensive, if you want to know more drop me a PM.
Bike is now making 12 hp above standard (without a spaghetti system).
The combination of the stage 1 Ducati ECU and the powercomander with a map of the website needed no adjustment, air/fuel ratio was spot on which is what they look for.
Shaun