I've owned 1 Mojo, 1 Supra both of those didn't have a surf pipe, the Supra I own now has one. It makes a big difference in exhaust note, especially under heavy loads when surfing. I also believe it makes a difference in the CO and exhaust when loaded down surfing. I don't notice the sulfur/burnt fried chicken smell when riding behind or on the surf lockers on my Supra with the surfpipe.

If it is coming from the factory...ABSOLUTELY!
If it was added aftermarket...I AM OUT!