I have Dynomax Super Turbos, and they did drone a bit between about 1800 and 2100 RPM. Not
at all as bad as the Flowmaster 40's that came off though! I installed Heimholz resonators a few years ago, and the drone is now negligible. I love the low, mellow tone that makes people ask if the engine is actually larger than a 302. (It's not.) And yes, a pair of spun metallic cats will quiet it just a wee bit more, and you won't have to take a shower after every drive.
If you search YouTube for "Steeda #19 cam idle" under user "ashemoski," you should find a video with idle and revs.
EDIT: Video link: