I've got a Magnaflow on my SRT as well but the shop fabbed up a true dual exhaust utilizing their [Magnaflow's] dual in dual out muffler. Mine is REALLY loud and sounds nothing like a 350z. It has lots of drone while under slight load but when you get on it the sound gets truly amazing. It took a while to get used to the drone but I have actually gotten used to it.
It's still alot quieter than my Fairlane with 3 chamber flowmasters and turn downs.