This isn't exactly a review or worthy of that title. Basically I recently went back to full frame and wound up with a Samyang 14mm, Zeiss 21 and Sigma 50 for new lenses for it. Before I settled there I had a 24L II and Canon 50 F1.4, and earlier in the year had a 14L II rented on a 5D III. I decided to make a page on my site noting a few things and reasoning on ending up where I did. Take from it what you will. Basically compared sharpness of the 1.4 and 1.8 Canon 50s to the Sigma 1.4. Then noted sharpness, vignetting and distortion on the Samyang and Zeiss.
I couldn't be happier with the Samyang 14 or the Zeiss(no duh on that one I guess). In the end I wish I had kept the Canon 50 F1.4. Sigma is sharper wide open but Canon quickly passes it even by F2.8. The Canon 24L II was great and sharp, but full frame coma was so bad beyond F2.8 it was sorta a lost cause opting for it for a fast night lens. Zeiss was wider like I wanted and no coma.
Most of the examples are gif animations too, for stopping down comparisons of sharpness, vignetting and distortion before and after fix.
It was never planned to do a review at all. Only later on with new different lenses I'd try and frame it like I had testing the others before.
Anyway, I now have these if something else was wanted done. Really just need to get the Samyang 14 out for night stars yet. The amount of vignetting at F2.8 I really haven't planned on using it much for that anyway.