Herbst's article is a great one. My reading of it confirms that while platinum may show more steps than Azo (but just barely) Azo has a far longer visual scale. That must mean that the platinum steps are closer together, which helps give platinum prints the "flat" look they so often have. That combined with the significantly shorter density range of platinum prints supports my contention that prints on Azo have a longer scale than prints on platinum.
Bu some people do prefer the platinum look. Which paper you use should always be a function of how you want your prints to look rather than by the numbers.
Michael A. Smith