2 strokes definitely have a better power to weight ratio, and they get up and go faster because they make power every other other cycle, as opposed to once every 4 cycles like a 4 stroke

the definite advantage that a 4 stroke has though, is that it's cleaner than typical 2 strokes. the disadvantage is that they are heavier and cost more, and i think not as perfected as most 2 strokes