What kind of sound are you looking for? How loud do you want it? Check out the sound clips here for different set ups.
No muffler = very loud, very raspy
Remove 1st or 2nd reso alone -- louder and more drone
Remove both resos and keep muffler -- louder yet and much drone.
Personally, I'm into stealth power. DP/RP no cats and three, let me repeat this, 3 resos and the muffler. Big power bump, as quiet as stock and almost no drone. I'm stock from the RP back, with an additional reso - straight through design, in line in the RP. The stock cat back exhaust is completely straight through design. No power gain in changing that unless you are going to go above 300 whp. No other benefit unless you just want a louder or different sound. Oh, and I did downsize the tip from 4 inches to 3 1/2 non-rolled. It's almost invisible, still larger than the piping and very anti-rice.
Each to his own. I'd rather be seen (my tail lights getting smaller) than heard. That's just me.