I can only describe ny own experience:
THe '61 Comet has a 250 with radical engine work including 272 Cam. I'm using Smithy 31"'s set behind the collectors and dumping out ahead of rear wheels.
On the Daily Driver mild 170 - '63 Wagon, I use NAPA generic small cans with JC Whitless "Turbo Mufflers" as resonators.
The mild 170 daily driver '63 with NAPA mufflers was metallic raspy at iidle and the wagon body "drummed" with side exit exhaust in front of wheels. I added the resonators and turn downs but am still not happy with it. I wanted to be as quiet as a dual header would allow for daily driving.
The Smithy's on the 272 Cam 250 with short turn outs sounds great. They cackle at idle without raspiness and sound open - but without the edge - rather than baffled under power. I don't think I'd want them for a daily driver without rear exits or resonators .
BTW - Both setups use standard NAPA pre-bents at @ $5 each a bend and standard 2" tube. Hangars are @ $2 each - NO BILLET here - strictly old school cheap shi#...
Powerband