Motorcycle Repair: Sonic spark plugs, spark plugs, mileage

Question
I have read advertisements about sonic spark plugs (cost varying from %5 to $* per plug.  These ads include claims for improved mileage and power.  Any truth to that?

Answer
i havent heard anything about these plugs, but a few years ago I read about a test on different plugs. The dynoed a bike with about 10 different spark plugs and found that all the plugs tested made no difference to power
Good luck and happy riding
Mike