I don't think he always operates at full speed which is a great ability to have in itself. Sometimes he runs or dribbles fast enough just to beat the defender but you always feel he could go up a gear if needed. You know those balls or crosses that get deflected towards the corner flag or look like they are going out for a throw in? He must rescue three or four of those a game, and each time I look and think 'that's going out', but then I see Mo running for it and then all of a sudden he's kept it in with ease.
His speed is astonishing, especially over a relatively short distance.