That's a tough call... I have 2 Conquests, but have not yet been able to afford an SHV. I want one, bad. But being that it's a NF, I will guess it is inherently a high-quality optic.
If you want adjustable turrets, the HD5 would be the way to go, if you want a rock-solid tank of a scope, NF usually wins in that category.
If it were me, it would be a matter of glass quality. If the glass is better in the NF, I would get the NF. If the glass is better in the Zeiss, go Zeiss.
For a hunting scope where game is involved, I like high-quality optics. For basic range, tactical, and target scopes, glass quality is not the most important factor, duarability is. Then glass, then turret quality.
I love my Conquests...But I REALLY want to try an SHV. I have a feeling it will be right on par with the Zeiss scopes. So, if you want a 30mm scope with a bigger 56mm objective, and a badass reticle (MOAR), then I would go with the SHV. If you want a scope with a 1" tube, 50mm objective, and a non-ranging reticle, then go with the Zeiss.