It's technically not a flaw. The older bikes had "eco", "sport", and a couple of other modes. the newer Easy Motion's now just say 30%, 50%,75%,100%, at least the two i have. 75% seems quicker than 100%. I suspect it's just the way it senses the torque sensors in that mode. Kinda like shifting your car down to 3rd gear to get the revs up and go faster. I'm usually in the 30-50 % mode anyway. I'm very range paranoid, even though the range on the 2 bikes i have is very good. But the 2 higher boost modes are quite addictive. Just can't wait for good riding weather. This winter will not go away. Got another blizzard coming today supposedly.