AFAIK, "OS2" IS OX platinum - just a specific set of diameter/wall thicknes specs that Waterford uses. Having owned and ridden a couple of Gunnar (Waterford's "economy" line) frames, one first-gen OS and the other OS2, I've found the OS2 to be a bit TOO stiff for my liking. And I'm not a small rider: 62cm frames, 6'3" and 180-200 lb. But then it seems I've always preferred "springier" frames, even in my racing days. That said, I highly recommend anything that Waterford builds. They know their stuff.

SP
OC, OR