I've had these installed from the moment I picked up my bike in March so I can't tell you how they compare to the stock, but they do not have the drone sound and are not at all as loud as the cobras. Nice deep tone to them. Quite a bit deeper and louder than my old GL1800 pipes were if thats any indication.
Here's a clip from their website. http://www.youtube.com/watch?v=kpjv2e-KyNI