Upload & Sell: Off
I have shot the 50 1.8D, 50 1.8 E Series, 50 1.4D, 50 1.4G, and Sigma 50 1.4. If the sigma has accurate focus, then there is no need to look elsewhere. If you don't have time to ensure you have a sigma that works perfectly, then either the 50 1.8 if you don't mind bokeh that is a bit busy, or the 50 1.4D stopped down to 1.8 would be my choice. I have no love for the 1.4G. Perhaps it was the copy I used, but it wasn't any sharper, contrasty or faster to focus than the 1.4D. I wouldn't use either at less than 1.8. So the only reason not to choose the 1.8 would be if you are very critical of bokeh. I chose to keep the Sig 50 (which still needs to be sent in for adjustment) and the 50 1.8 to fill in when I need to make sure I get the shot.