I bought the 85mm 1.2 II because of its ability to shoot @ 1.2.
This allows me to take very creative portraits. It's a heavy and slow focusing lens (relatively speaking).
I personally don't understand comparing 1.2 lens to anything else but 1.2 lens.
Stopping down to 1.4 and comparing at 1.4 to the sigma art doesn't make sense to me.
I have a Canon 50 1.4 (and had a 50 1.
. I would consider it a fair comparison to compare it to the Sigma 1.4.
I quite like the Canon. It's not the sharpest at 1.4 but it has a lovely vignette and creates a nice look.
If I were buying a canon 1.2 it would only be for its shallow depth of field @1.2. If I was going to mainly be stopping down Id buy the 1.4 or 1.8 which are much lighter.
I love all these types of discussions and comparisons because I always want to know which is the best.
But I am also experienced enough to know a bad workman blames his tools..
A 50 1.2 might be better than a 50 1.4 but I like 99% of the members of Canon Rumors are not good enough to show this in real world photos.
I got up at 05:00 yesterday morning and took out of focus photographs of a beautiful sunrise over the sea with a 24mm TS-E II. It wasn't the lens wasn't sharp.
It was the brain of the photographer .
But it was a wonderful privilege to witness the sun rising. That memory will last a lot longer than the out of focus photographs.
Drop the charts for a while and try it for yourself.
But keep these discussions going because they are enjoyable too