I have the Zeiss mentioned above, and the Meopta Artemis but in 3-12x50. The Zeiss is a whole heap better in every respect, when compared at like magnifications....and I prefer the fact the reticule stays a fixed size in the Zeiss as you zoom, though this is purely a personal choice with me shooting small things. The Meopta is probably more a medium game scope though, so this wouldn't be an issue there.
I also have a Nikon and a Leupold, and after a bit more playing, I'd say the Zeiss is optically the best of the lot (Though only by a minimal amount to be honest) and build quiality on a par with the others. I've had a look through a few Swarovskis, and they are a league above again...