PhotoPass pics are taken with a Nikon D70 at 6mp, so the resolution and color are excellent.
Lighting and framing depend on the skill of the photographer. I have seen some great PhotoPass pics and some that stunk. But the PhotoPass photographers are constantly getting more training to improve their skill, so the stinkers are becoming less common.
Print quality will depend mostly on the quality of the place where you have them printed.
These are my two best PP pics from my last trip (click the pic to view the full-size version):
