Well, just my opinion but I think the baffled Cobra system sounds absolutely mean.
It sounds like a hot-rod small block V-8. I love whacking the throttle when I ride Kim's bike! It is a little loud for my taste while highway cruising but Kim loves it & it's her bike.
My glasspack job doesn't have the V-8 rumble that the Cobras do, more of a V-12 Ferarri-like higher pitch sound. Some folks tell me it sounds like a P-51 Mustang warbird as it rolls by under open throttle. I used short body {16"} glasspacks that dumped into the slash cut tips.
I found that on long trips the GPs were "droning" too much for my liking. I figured it was because they were resonating inside the 4" tips. So I made some 2" extentions that I put some car tips on to move the sound out of the 4" tips. Also added just a touch more backpressure which I thought it needed. Worked out great.
No dyno confirmation but my "butt-dyno" says the glasspacks added a bit more mid to upper range HP over the stock system with no loss of low end grunt. Same butt-dyno says the Cobras hurt the mid range noticeably & make the well known Valk flat spot worse.
One day if I ever have to re-do my GP set up or do another Valk I would like to try some longer bodied glasspacks to see how it works. I suspect it would be better, deeper tone, less drone & maybe even better low end torque.
Overall the GPs are quieter than the baffled Cobras.
