There is enough low-end grunt to start off in second gear, although first gear is much more satisfying. There is ample torque in the powerband where the car used to be on the borderline of bogging. During daily driving I don't have to work the engine hard in order to achieve the performance I want. Now I just roll on the throttle and away I go. The exhaust note does seem to be a little bit louder though.
Many people seem to be wondering about how the bypass system works.
It does not require wide open throttle to break the bypass valve. Just mash the pedal and you're off. In addition, my gas mileage seems virtually unaffected. My mileage on the street seems to have decreased by about 1-2 mpg, however my mileage on the highway has increased greatly. I recently filled my tank up and drove to Pomona and back again which is about 120 miles.