Scholes was better technically, his touch, close control, his interplay in keeping possession, vision (as with Gerrard), passing, long balls (as with Gerrard), had a good eye for goal, was game in defence (could have worked on his actual tackling though), not necessarily the best dribbler but neither were Gerrard and Lampard, big match player (but so was Gerrard) etc.
Gerrard was more dynamic, better leader, had a great shot on him, got around the pitch better, both played various roles as to what was required etc.