Adding weight to the rig would take away from the action. It falls very slow and that is part of the way its fished. A fish may not want to chase something thats zooming downward past them. But if they see it falling slowly towards them it looks more natural and they don't have to expend as much energy to catch it. I'm sure its been tried both ways, and if the slip bobber worked as good, then everybody would be using it instead of doing it the hard way.(it aint easy casting out 10 to 14 feet of line with a fixed bobber)