I would go w/ the viper over the razor. I'm not a big fan of that movable bar on the razor, looks like a weak point to me. I have the viper and absolutely love it.
I must respectfully disagree with you. I have the Summit Razor SS and the bar is not weak in the least. I really like that it can be moved out of the way after using it for climbing. The Razor offers the best of both worlds in my opinion.