I use to run a 70mm invidia TP for a year or so. I've also got a dual invidia v3 installed. As far as drone goes, the test pipe quieted that down. At WOT it got crazy loud but for some reason it felt like i lost power due to it.
That and police seem to be manufacture racists (jap cars) where i live. I'm not an ignorant throttle masturbater or street racer, but to police, sound and image is enough. It makes the S much louder in my experience.

+1 on the smell at a stoplight lol

 

For me, with the stock exhaust and Berk TP there was no difference in drone, the drone is from an aftermarket exhaust and those vary a lot.