I haven't checked out a pic of the commercial rack for a while, but from memory the only significant advantage over the MMPR rack is built-in plate storage.
You just have to ask yourself if this feature warrants the extra cost. I've got the MMPR and lean all my plates on the side wall of the garage. Very easy to access and takes up stuff all room. Personally, I wouldn't be paying extra for the commercial rack....although I do like the look of it...sweet piece of equipment.