I've read a couple similar articles. Both (wish I still had the link) put the big three in this order, best to worst (keep in mind there'* just a couple hp seperating them):

Magnaflow
Dynomax
Flowmaster

I know this is going to stir the pot a bit, but that'* what I read, and my exhaust guy told me the same thing when I went shopping to complete my exhaust. My exhaust guy also told me he put a Flowmaster 80 on a 95 Buick Riviera (Supercharged), and the customer brought it back (not happy with something, forgot what.....sound, performance, dunno). Jerry put on a Magnaflow identical to the one Ihave, and gained 4-5 hp on 3 consecutive Dyno runs.

I would, too!! I had true duals on my V8, 351 (5.8L), sounded hella good!!!

ok.....to sum up my thoughts
ALL magnaflow, flowmaster, dynomax, etc. mufflers will flow better than stock and to some extent add horsepower.
ALL will produce different sounds, which will be based on personal taste.

As for your flowmaster rusting vze3r85p, chit happens i guess. I just don't see how you can come off and say for people with flowmasters to DITCH them for dynomax because that'* what you think is better. Everybody is here for the same reason, I think.

Everyone has had a chance to say their piece now.

I believe Ryans question has been answered, you need a glass pack, BusMaster007 summed it up quite nicely.