If the 570 your test rode still had the factory exhaust an on it, THAT is the reason you did not get the raw/wild/visceral riding experience you were hoping for. Guaranteed. The factory can is preposterously restrictive, and the bike is horribly overmuffled and hamstrung as a result. Short of gutting the can and eliminating whatever modest spark arrester capabilities it had, there is nothing you can do to the factory can that will let the bike run like the engine designers intended. Mount an FMF 4.1 and the best rises from its sleep.