You'll get a lot of negative feedback about Vortex Riflescopes on here. I actually like their optics a lot and think they're a great company, but concur with the advice to avoid their Philippine and China-made riflescopes, which means all of the Crossfire, Viper and Diamondback lines. I've owned multiple scopes from the latter two of these, and thought the optical quality was pretty good, but had several POI shifts on guns that did nothing but sit in a climate controlled safe that nobody other than myself had access to.
Their spotters, binos and Japanese-made riflescopes (Razor line) have been great in my experience, but I got rid of all my Diamondbacks after the POI shifts happened.