A DW, stinger, or a sutton all run differently at the same speed. A sutton may run perfect on a given day @ 2.0, and a DW @ 2.6. both should catch the same fish. Optimum speed for a particular lure may be a better way to look at it. IMO, but like Nick said, 2.1 - 2.6 is a good range for me as well. Pay attention to hits on turns, if the outside rod goes more often, they probably want it a little faster, inside rod, a little slower.