Rectangular design allows for arrangement of your pots as you choose -- according to most-used pans or for visual pattern.  Very useful to have the top available for lids, books, decorative somethings....  

Pros: Helpful solution to cramped or inconvenient cupboards, looks good, has enough hooks, has useful shelf.
Cons: Needs knowledgeable handy-person who has proper drills and takes care to find studs to support not just the weight of the rack but all pots likely to hang from it.