Try to get the opportunity to look through both side by side, you'll soon see why I favour the Zeiss Jena over the Vortex.
A great warranty is indeed great, but doesn't find deer, the quality and clarity of lenses and coating is the thing that matters. In the event that the Zeiss glasses take a knock and go out of collimation, it's a straightforward relatively inexpensive repair, but this is by far a secondary consideration, the strap is for keeping them round your neck when in use on all; performance is uppermost in my mind when I choose, personally speaking.