Well I was origionally looking at a Beowulf or Blue Flame, something cheap and cheerful just so I can actually hear the engine. I am not really fussed about performance increases as I am yet to use full throttle anyway
I thought the M4 sounded the best from the clips I have seen on youtube but I don't really want to upset the neighbours and can't be doing with being pulled over everytime I go anywhere cause the bike is too loud.