depends on the depth of your pockets, in the UK loads of people go for the Akrapovic full system but there have been muted responses when you compare power to price, Micron do a full system too, again muted response, these 'first to produce' manufacturers have not really hit the jackpot when it comes to power, however, Arrow produce 3 systems , 2 in stainless and one full titanium, the road stainless version has no more power than the other manufacturers BUT at least a third cheaper, and italian quality to boot... there is another alternative however, that being Mivv, Mivv produce a full system for the R6 2CO, they also produce exhausts for the Honda Moto GP works team, they chose to wait, research and test, as opposed to just 'produce to market' the result is an exhaust systen that produces between 11-13 bhp at peak, and a truck load of badly needed mid range, also the Mivv comes with an O2 sensor boss and closing off bolt, this means you can run either a PCIII usb (with the nut in and O2 sensor removed) or you can go for a closed loop fuelling system such as either the Bazzaz or the Motty AFR tuner, this is most certainly the better system, no dyno tune needed and the system constantly remaps itself to fuel the engine to a pre programmed air fuel ratio...dogs bollocks basically