If you do go the molly route be careful. Most items will require two that are fairly close to each other. Those holes for the molly's will be fairly large leaving a very small space between the two holes.
I've seen that area fail when someone pulls hard on the item (i.e. towel rack)and then you're faced with a large hole.
Would be nice to fasten to a stud, but sometimes they simple are not where you want them too be.