I don't find my RS-3 with the baffle in to be much louder than stock under 6000rpm. It's not 'sneaky quiet', but you won't alarm anyone. Baffle out is a different story...

 

The TRS is a bit different then.
I slapped the baffel in and quite frankly, it sounded muffled but pretty much the same.
Then again, I hardly ride under 6K rpms.

 

I hear ya. It's only when I put the baffle in that I try to sneak around under 6k. When it's out there's just no hiding it so why bother!

Here's a video of the RS-3 no baffle. I switched from camera mic to a wired mic under the seat at about the 1:00min mark. You'll notice when the wind noise goes away.
http://www.youtube.com/watch?v=ima-HCppDtA