I have the 18" stainless pipe (oval). Pulled the baffle and never looked back. Sounds nice and quiet until I twist the throttle (hard). It's just that little screw holding it in, but it's sticky, so you can pry it slowly with a thin screwdriver in the hole. Use leverage, we're not cavemen, and then you won't get hurt when it comes free.
I do notice a little extra vibration in the handlebars at around 90mph in 6th gear, but I'm starting to think I should sync the fuel injectors before looking elsewhere for the vibrations. I know if I pull in the clutch and let the motor idle it goes away completely, and I don't remember feeling anything until recently.
Any thoughts, guys?