Hey guys, I'm getting that GAS attack and what I'm looking for is a good 21mm M Mount to use on a GX7 (m4/3). It'll give me a 42mm view with that crop and should be a nice street combo. I'm interested in the Voigtlander Color Skopar f/4 because of the price, but Adorama has a used Zeiss f/4.5 C Biogon for $669. Is it worth it to go with the Zeiss or will the Voigtlander be good enough? thanks!