That looks pretty damn good.
The other thing you might notice with your images is 'trailing' in the corners and along the edges (not obvious in the shots you've taken and uploaded though you can see it at the top of the crop image). Stopping the lens down can help reduce this effect but it also slows the lens down.
The 17-85s aren't particularly good lenses for AP (but better than nothing
) and they will usually show this with stretched stars in the corners and along the edges.