[Klaus]

Thanks for the explanation about refocusing the corners. Wasn't sure about that.

 

So getting those gazillion complaints about how much people would shoot wide open with main subject in the corner does also say something about the importance of corners sharpness with this lens, doesn't it? Rate it the way you like, I'm aware of comparing Nikon and Sigma in the Canon board and grateful not to be thrown out.

 

And now, since I checked, I'm also aware of a price gap of 500 francs between Canon and Nikon version. And since you rated the Canon version already, the situation is different because Canon is not asking 100% more. 104% to be accurate and that goes with a bundled polarizer on the Sigma... yes, a Sigma polarizer, not a China copy.

 

Ratings are ratings - technical findings have a limited overlap with the real life. How limited depends on the use case. 

We can't do the scoping for the reader. 

 

If you want to have the sharpest Canon 50mm lens at f/5.6 on full format, you may choose the el cheapo 50mm f/1.8 STM. If you want to have the best bokeh, the the "bad" 50mm f/1.2 USM L may be your choice. The technical rating is irrelevant then.

 

In the real life I reckon I am a bit on your side. I'd use the 24mm f/1.4 at f/1.4 purely for shallow DOF thus the corners are irrelevant. I'd also use it stopped down to f/8 for infinity DoF which is where it's good. Thus within this usage pattern, the Sigma is fine. If you are taking pictures in a theatre (low light) you may prefer to have a lens with better borders just as an example.

 

Thus do your scoping and live happily ever after.