I do have a Diamond Eye on mine with the muffler. "Muffler" is a stretch though as it is straight through. The resonator did change the sound a little but still sounds good. If you do go with a resonator get a free flow design so as not to increase back pressure and EGT's which is why you buy the larger exhaust to begin with. Install was a breeze!

 

I like my DE with muffler.

 

Mine came with a muffler.

The only thing I can say I don't like about the DE 4" is that when I'm on a highway, based upon where the pedal is, and how aggressive, or not I am with it, the muffler resonates into the cab. Kind of an annoying buzzing sound which is changed / or eliminated by depressing or removing the foot from the pedal. Guys on the site here tell me it's from the muffler, and that's what it sounds like. Stupid resonance !

Other than this, my DE exhaust has worked out great.

 

Mine rattled at first but after some adjusting it doesn't rattle anymore. Well worth 300 bucks.

 

I just did a cab back 4" exhaust with a mbrp muffler for the moment till I get money to buy a kit. It seemed to drone quite abit. It all went away when I put the hx 35 on it. Now its got a annoying whistle.