If your asking listed daytraders who trade in/out, hybrid is a big negative because so many listed daytrading strategies were based on the specialist system. I see the loss of price improvement at market order to have effect on daytraders who average less than a nickel profit on total shares traded for the day.
Quote from cypresspoint16:
Does hybird make the specialist less influential, and at the same time smooth out price fluctuations? Has the time frame for scalping been lengthened. Forget the 1 & 5 min charts?