I have had three Nikon scopes, and I still own two of them. I have never had anything go wrong with them, so I can't tell you what their warrantee service is like.

Nikon makes a nice scope. They are bright and clear, but their eye relief isn't what a Leupold has. The Leupolds I have used have all had VERY forgiving eye relief. The eye relief is only negative comment I have about my Nikons.

I am looking for a scope for my new rifle, and I think I am going to shell out the clams for the Leupold VX-III.