The cheats always have a way of justifying their behaviour - everyone else is getting away with it, so why shouldn't I? But because they're so reliant on the drugs - and the drugs are not always perfect, you're not guaranteed to peak at a big event - they don't have the confidence to look in the mirror and know that they can go out and give their best. If you're clean and you've prepared well for a race, that's where you have an edge.