What's wrong with this? It's probably screwing up because you have useless edge loops there. EDIT: There's a little bit of pinching there, but an extra control loop below it would fix that.
No edge is ever perfectly hard. Just put the edges really close together to harden it out. That four edge loops approach renders well, but it's ugly otherwise. If your doing this piece to show off good high poly modeling, I'd recommend against it. At the very least, use separate geometry and try and fix your AO bakes you…