I am using a Sigma 50mm ART lens that has been perfectly calibrated to my Nikon as a reference for this lens. As long as I like it Handling is excellent and overall it feels like a very high quality product. It's not as sharp as the Sigma, but it's not as big either: 1.2 vs 1.4. The bokeh is more interesting than Sigma's in my opinion (but maybe a little less "nice?") and the colors look really good. I like 40mm because I'm always torn between 35mm and 50mm, so it helps get rid of some choices and the temptation to buy more lenses in that range. The decisive factor is whether you value a technically perfect picture. and bokeh like that created with Sigma ART or Sony's newer giant 35mm lens compared to something more distinctive/individual and less ridiculous on the A7 series. Manual focus isn't a big deal on the a7 series, so don't let that hold you back. The manual does not say how to snap off the aperture ring. You have to move everything towards the camera and rotate it 180 degrees. I will probably never switch it to click mode again as I can see the numerical value through the Sony viewfinder.