It sounds to me that with the type of shooting that you do the ZE 50 f/2 MP, would be a better lens for you than the Sigma. I think it is worth a try. By the way, I think the ZE 50 f/1.4 Planar is weak at close distances and especially close up, but is stellar at further distances and especially when stopped down. It is a great lens if you know what to use to for and what not to use it for, and Zeiss has smartly made the two fifties complementary in their strengths. The 50 f/2 has fewer weaknesses, but is not quite as good as the 50 f/1.4 at distances and stopped down, IMO.

I think I will save up for a Zeiss 50 MP in addition to my Sigma 50mm, that seems to be the best course of action given that I do shoot a lot at 50mm and will be able to justify 2 of them. If I notice I consistently use one over the other, I will just sell the other one.

Thanks a lot for helping me make my decision, everyone!

The Zeiss 50 MP will be sharper in the center, sharper in the mid-frame, and sharper in the corners. It will be sharper at f/2.0, at f2.8, at f/4.0, all the way up. It will show you better color and contrast. It has semi-macro close focussing. It has better build and superb autofocus control. It doesn't have AF, and it doesn't do f/1.4.