I just picked up my 2015 F6B

[bigbird]

Definitely more rumble at idle.
As another new '15 owner has stated, at higher rpm it doesn't sound much different than the older models.
I'm still waiting to hear real world feedback on the forthcoming Two Bros mufflers.

[nvmyf6]

Definitely more rumble at idle.
As another new '15 owner has stated, at higher rpm it doesn't sound much different than the older models.

I agree, it sounds great at idle. It does sound better cruising down the road then just sitting there at a higher RPM level.