Chris--On my SS, I have the Ultra Flo mufflers w/cats and H-pipe, but no resonators. Had it custom bent by a good local shop used by most of us NASSA members. Probably similar to the kit you're looking at, but not mandrel bent. It's not loud compared to many of the mufflers out there, but it was louder than I wanted on my Fleetwood, so I used the same setup, except I switched to Dynomax Hemi Super Turbo mufflers. Much quieter, and still seems to flow pretty well. On the loudness scale, I'd say it's slightly louder than the stock SS was. Not noticable in cruise mode, but can be heard just a bit when accelerating. The Ultra Flo, on the other hand, can be heard when cruising and is quite obvious when under load.
Hope that helps.