In reply to Bruise Apprentice:
The Puma doesn't have double waist buckles (well, mine doesn't).
But Google suggests that the double waist buckles are basically intended to do the same thing as the "floating waist belt" on the Puma, i.e. letting you adjust it a lot while keeping the belay loop central relative to the gear loops. And I've found it generally comfy and well-designed.