My answer...it depends. I've caught fish that wouldn't bite until after being stirred up and had fish go off the bite after being stirred up. What sleds do that is known to be bad for fish is erode the banks. Sled goes by full blast the waves erode the banks and often times silt the holes. Anyone seen boat launches gouged out by sleds running up on the trailer? Every time they fire up on plane they are doing some damage to the river. Also, anything that can run in six or less inches of water at full throttle can't be all that great for the fish either. This is why they should be restricted to large rivers only imho. That said I too am a hypocrite and wouldn't turn down a free sled.