A little more info for you guys considering D and D slip ons.
I rode about 75 miles without the baffles and it's unpleasant at high speeds. I decided to test with a decibel meter and this is what I found.
Idle - 98dB
2000 RPM - 110dB
With Baffles (and this surprised me).
Idle - 101dB - Yep, with baffles the Stratty achieves a higher dB
2000 RPM - 104 dB
But overall, it's just a cleaner and deeper sound with less popping on decel. The baffles are back in to stay.