dyno-max mufflers good / bad?

I have had them on both my 318 and my 340 Darts. The ones on my 318 finally got a rust hole in one of them after more than 20 years! I called jegs and got the same mufflers again! I like the quality and volume of sound. I spent a pile putting Flow masters on my 340 a few years ago and don't like the sound as well. I'd rather have the Dynamax turbos back at a fraction of the cost...