I have had both, looking for other opinions. I have a 2006 F150 Super cab 5.4

 

The only con I had against dual out the back is because I pull an enclosed trailer (alot) and didn't want the exhaust slapping off the front. I could have went dual out each side but the SO was cheaper. lol

 

I went with a single. I tow a toy hauler and was told that I would lose some of my pulling power with duals. I have a flow master and it sounds great.

 

Single should give you more power. but duals is louder!!

 

duals if done right will gain both torque and hp

 

I have the Heartthrob which is a straight pipe from the y-pipe, with no muffler.

 

First I replaced my stock muffler with a Magnaflow, and really liked the sound, just didn't sound quite as loud as I wanted it to, went to true duals with a pair of maggies and high flow cats and LOVE the sound (clip in sig). Looking for a little louder now, so I'm probably going to delete my rear cats.