Mine arrives todayAt the moment the system lacks a proper wide angle solution. With my A7 I purchased the FE 55/1.8 (no brainer) but also the CV 21/1.8 (manual) as I can't work without a decent wide angle. A highly recommended lens.
I'm going out on a limb and pick a lens I don't have: Voigtlander 40mm Nokton. It just looks like so much fun!