Um, im very partial to supersprints simply because they are designed and tested units, fit perfectly and are quality items. I dont rate many other manufacturers.
But you wont get a power gain or anything, the std system raelly is that good, the only restriction being the HUGE rear silencer. We tested one with a diff exhaust and get a peasly 2bhp....so......
to get any sort of real power gains, you really really have to work on the inlet system, the engine is perfectly good apart from that.