I am not surprised at all. I use both. 50mm is a better lens. Both on sharpness, low CA and low vignetting. Also it is a OSS lens. 700$ less than Zeiss is the last reason that makes it again better than 24 zeiss.
In fact I would vote for sel35 f/1.8 to be again better than 24 zeiss too. I also own this lens. It is significantly smaller than zeiss and costs less than half. Performance of this lens is minimally worse than zeiss that everybody can live with that.