I have the razor angled too. They're HD glass all the way through, while the viper is (very nice but) only HD in the objective lens.
Depending on the day I'm comfortable with my Razor out to 1000 easy. The only thing limiting it is heat waves and mirage on hot days.
Is it as good as a swarovski or a leica? Not quite, but it cost me a fraction of what they would.