Of the choices you list, i would go Nikon. I am a DIEHARD Leupold guy, I own 2 Nikon Pro Staffs and they are just as clear. As for Rugged, Reliability i Say Leupold ALL the Way. Personally I would avoid the Vortex Crossfires, The Crossfire line is made in China, If i were to go Vortex i would at least go Diamondback, or better yet, try and Catch a Viper on Sale.

For the most part I believe you get what you pay for with Glass such as Scopes/Binoculars etc. Believe me, I know the Feeling of Spending more on a Scope than a Rifle. I also believe, and have witnessed it first hand Where The Rifle was only as good as the Optics on it allowed