I am also a fan of the quads, but believe me when I saw we are the minority.
The single and dual exhaust from Kakimoto came out at the same time. I chose the single since I don't really see any purpose in having a dual exhaust on an in line engine. Also the dual weighs more and it costs about $400 USD more than the single.
I couldn't have said it better myself! I do like the dual look from factory and Mitsubishi did the right thing for its design. However, "upgrading" causes me to go single and big.Form over Function, or should we do it right? On an L4 there is no purpose for dual after cat (not that there is ever a purpose for fake dual). Its extra weight, and by swapping to the single outlet catback alone you can drop 20+lbs.
I like the look of dual, but extra weight isn't worth the look.