i always wondered the same thing, i decided on the duals 'cuz they keep the stock look. havent had time to install it yet tho....its just chillin in the box in my garage. duals for the win! haha

 

i believe i will go with the dual if i buy them... i did hear they restrict the flow but so little that its not even noticable(steve kan said this).. i am thinking if buying it to go with rx7 store but my friend ordered an exhaust from them before and it was a while before he ever got it.. so either rx7.com or rb themselves only a 25 dollar diff..

 

Dual tip all the way....I can't imagine there would be a significant sound difference. I too chose it for its close resemblance to stock. I have a 3" DP and unresonated midpipe. The idle is a bit throaty, but sounds great. Revving the engine takes you through a harsh, raspy set of frequencies, but the top end sounds phenomenal....especially going through tunnels or enclosed spaces. My only addition will be a high flow cat in a few weeks, which I hope may knock the edge of that raspy sound.

 

Dual Tip.... I love the way it sounds at idle and cruising. When I open it up, you can definately hear it back there. I think the single sounds and looks a little bit ricey. Just my .01.

+1 dual

 

Looking at just a cosmetic reason...I would go with a single because cleaning between the two pipes coming out of the catback is usually tight and if you're not thorough, it gets dirtier and eventually that's where it will begin to corrode or pit mark.