I have a janny dtm on mine, best thing I ever bought I think, for the car.
It felt like it allowed more torque at lower revs, and I know this sounds odd but the fuel consumption was better too, and I use a standard airbox and filter on the inlet side.
As regards the sound, its not loud - I have it fitted to a standard mid pipe that has the small silencer on, it has a nice smooth sound to it and doesnt sound like a "wasp in a coke can" like some of the universal silencers that are around do, at idle and on over run it sounds lovely
I bought mine secondhand of here, I have never had janspeed before and I was very impressed with its quality
One tip though, use a small rubber donut at the mount under the bumper, I found a better fit like that and I also bent the towing eye up out of the way, otherwise it will knock like crazy on it.
