Take "maximum depth" with a grain of salt. How many rackspaces have access to this maximum depth and how many are much shallower due to components (like power supplies) eating up that depth?

Before you buy a case, research it thoroughly even if it means emailing the manufacturer. Nothing will destroy your rack layout faster than a miscalculation of actual depths of your case and the reality of your modules and how you'd like to place them in your case.