I have the Dynomax Super Turbos (the ones with "flow directors") on my Hemi RR 2.5" system w/tips, and they have a nice crisp but not tinny sound, no drone, sound great. I'm putting a pair on my 3"-system BB wagon street strip car too.
Had a 406" Duster, 2.5" full exhaust & tips, that had Flowmasters or a knock-off of them on it, very similar sound quality to my Hemi car but no drone.
(To run 2.5" through factory tips, the tip inlets are too small, cut them off and weld to the bulged area.)