I own a 4.5-14x44mm Zeiss Conquest with their target turrets. Mil-dot reticle. But I don't own a Vortex PST. The Conquest glass is good, and turret tracking repeatable and consistent so far. A lot of scope for the money. Well, I should qualify that by saying I don't know what they cost now. I bought mine about 5 years ago for about $600.
I own three (3) Sightron SIIIs, and the glass in the Sightron SIIIs is slightly better in light gathering and resolution, in the direct comparison testing I've performed. My SIIIs are a 6-24x50mm model, with a slightly larger objective (50mm versus 44mm on the Zeiss Conquest). I thoroughly compared the scopes with both set on 14X at 300 yds in both good light and in failing light. There was a noticeable, but not substantial, difference in the quality of the glass. The glass quality in both scopes is pretty good though.