I've had 3 different aftermarket exhaust on my 350x's. The DG complete setup is a good deal for the money on ebay. They look the best, especially the chrome and it's only about $240 for the head pipe and the tail pipe new. The performance is good but they are EXTREEMLY LOUD and have no spark arrestor. The I have had 2 different super trapp set ups. They both have tailpipes that slip on to the stock head pipe, then the silencer slips onto the tail pipe. One has a larger silencer that slips onto a strait section of pipe. This one hits the rear break resi so you have to move the resi to the inside of the frame. The other one has a bit smaller silencer that slips onto a "coned" section of tail pipe that fits perfect with no modifications. The super trapps can be "tuned" by adding or removing disks to get what you want, and are a forestry approved spark arrestor.
I think if you took a poll on the subject, the super trapp would come out on top.
YAMAHA 450 HYBRID
85 350X- RED
85 350x -BLACK
86 350x-WHITE (with Goki)
85 250r
83 atc 70
84 atc 70
84 atc 110
09 yfz 450
2006 Arctic Cat Prowler
RZR XP 900