Hmmmm...I don't see why this is any surprise. I have only been printing with pt/pd for a few months and it is clear to me the tonal range is compressed. As a matter of fact it is clearly explained in the Arentz book. The platinum particles are in the paper and as such they "trap" light thus the lower reflectivity. The "flat" prints Michael mention are mainly due to a poor choice of negative rather than the inability of pt/pd to produce luminous prints. Terry King made a comparison of black from a pt.pd print and a silver print and most people thought the pt/pd had "deeper" blacks than the silver print, even thought the D max is only 1.4.
IMO pt/pd is better for high key negatives where the light tones are more important than the shadows, while azo I suspect is better for negatives with a long tonal scale and lots of "grays" where the dark and light tones are used for accent rather than an integral part of the "message".
The prints are very different and should be used for the particular "style" of the photographer. Trying to compare Azo to pt/pd is like comparing apples and oranges, each have their own taste and qualities. To say that either one is "better" or capable of yielding better prints than the other I think is foolish.
I applaud Bob's open mindedness but I really think this was more an exercise in sensitometry than a comparison. What is next? Azo vs POP, or Pt/pd vs Kallitype?