MBRP Cool Duals sound better with a muffler delete pipe?

[Tookie]

I have a 2005 2500HD ECSB 6.6 with only 14k miles on it. It is pretty much all stock other than putting 3" lowering shackles on it and cosmetic things. I have a Cool Duals down pipe back stainless exhaust that has the cat delete pipe with it. My question is will the truck sound better with the muffler on it or would it sound better with a muffler delete pipe on it which I think MBRP makes for it. Does the muffler being on it take performance or anything away from it? I really just want the exhaust for looks and sound and maybe help with gas mileage but I have a diablo predator tuner for it I might put on it from time to time. I also hope me lowering the rear of the truck won't effect the way the exhaust fits. THANKS!

 

[RitzBlitz]

The mufflers on the duals seem to be a little shorter than the other mbrp mufflers. I honestly like mine over my gf's straight piped LBZ with duals. I'd leave it on and throw a downpipe on as well, gives it a very unique sound for being just another stock fuel/air duramax with a 4" exhaust imho.

 

[WI Huck]

The muffler is not restrictive in that application. Leave it on and you will like it. There is more rumble than a single system because the muffler is shorter than the single system. No muffler will give you too much drone in my opinion.