Just an update for anyone that cares (like Fast 380), went for a good ride today, so in total about 500 miles on the Crushers.
They are growing on me- I still wish they were louder at idle, but in every other situation they seem louder than my initial impression. Not sure if the packing has broke in already, or if it's in my head. Overall they sound pretty good with a lower (deeper) tone than the Fullsac's, and maybe a touch less volume (than the Fullsac's WITHOUT baffle material).
I will definitely keep them on for the rest of this season, and either later this fall or next spring I will make the trip down to PA to see my tuner and have a "clean up" tune done. It will be interesting to compare the curves/numbers between the Crushers and my original chart with the Fullsac's. Once I do that, I will have custom maps for both mufflers, so if I ever want to go back to the Fullsac's, I can simply flash my original map back in.