MH good question, he must be thinking of Lee's match up........
I have a full ti RS3 from Yosh, superior fit and quality.....(7 lbs)
The pipes available do not offer any "Great gains" like we saw in the eighties and on. Suzuki did a great job with the OEM system that is why you do not see such BIG NUMBER GAINS.
Horsepower gains from the pipes available should be kept in context, euro busa with cat converters make big gains with a NEW system - bikes here in the states see lower hp increases for the same reason (no cats, in US spec bikes).
You want horsepower, cams, compression, and a pipe.
Yosh makes 200+ with OEM bores.
Carpenter offers a $6,300 205rwhp Busa (1390cc).
Mr Turbo, $3500+ plenty of power, more than anyone needs.