Presets are good as the sounds you make, both are good ways, the real challenge is to arrange them in meaningful ways and correctly. Of course, don't jump at presets blindly but know how to tweak them as needed. However, I feel certain sounds should not come from presets. In dubstep, for example, I think every producer should make his own basses/patches, maybe imitate other existing sounds, but don't just download and use patches from sample sites, because in dubstep, especially in the drops, sound design is key. This is only my opinion tho, then everyone does whatever wants.
