Originally Posted by snrusnak
There is basically no real performance difference between just a muffler swap and the full cat back. If you get the full cat back, you lose the resonators. Last thing is you get the bigger tips with the cat back. You should be able to make your decision based on these differences. IMO it's not worth the money, no real performance gain, and I personally don't care about the tips. If you want the tips it may be worth it to you as I understand they are expensive separate.
I tend to agree with you here. The guy who owns the muffler shop that I'm probably going to use to make my 3" inlet pipe for the muffler swap said that those resonators help keep a lid on an obnoxious note that the hemi tends to make with a low restriction muffler. The one I got to hear with an 18" Flowmaster and OEM tailpipe and resonators was about on the edge of what I'd want to listen to, and the Flowmaster is a chambered muffler. He said the straight-through models like Magnaflow, Borla, etc. usually make more noise...especially after some time. If pure performance output is the main priority, I guess this is a moot point. If your neighbors and your wife are going to give you grief, then maybe one should be concerned about the noise level...LOL! Serioulsy though, I want as much performance as I can easily and economically draw out of my hemi without too much drama and too much money.
However, we all know how subjective noise/sound is. I said somewhere else that one man's obnoxious is another man's symphony. Kind of like rap music vs. country & western...LOL!