While I can appreciate all the technical stuff, after a while it does grow wearying. Almost like arguing that one fish hook will catch more fish because it has a sharper point and its barb is 2 millimeters longer.
Today I did two events, around 1000 pictures, almost all with the Sigma 35mm. It makes me feel almost giddy with joy. On a 5D3, it's like there's no picture beyond my reach (at least within the focal range limits). I'll bet if I had a Canon 35mm I wouldn't feel much different -- but I do love this extra money I have!