I purchased this because it can be mounted multiple ways.  I was hoping to clip it to my upper cabinet but I found that my cabinet base was a little to wide for it.  I ended up clipping it to a lower cabinet door and although it's not the perfect place for the paper towel it works in the space I have available.

Pros: Easy to infall over door or under cabinet.  Multiple options for mounting.
Cons: Sometimes it doesn't roll smoothly and I have to tug a bit to get the paper to turn. Not a huge problem but a small inconvenience.