We've got this sort of office setup right now at my job, and I like it, however as has been mentioned it does get loud. It does, however make it easy for collaboration among colleagues which is nice. I would go over a foot though, as most people sit back in their chairs or hunch over you can cut down on a lot of noise by going even 2.5' over the desk height, while it still allows for the collaboration when they sit up.

-Jonathan.