Well, after doing all the free mods, I decided not to disconnect the grey wire, ride awhile and see if there is a big difference when unplugged. Since most people do all the free mods at once, there was no info on just the isolated grey wire mod results. After four rides I finally pulled the plug and must say the mid range is at least 75% stronger. Huge difference. The reason I decided to do this, is because of the debate about "is the Canadian model the same as US since some dealers were saying that on the Canadian model you didn't have to unplug the wire". So, if you haven't done the wire mod yet... don't hesitate to do it. You'll be really impressed.