This lens sounds great, but i'm just a little surprised that nobody thinks the price is high at all.
I don't think it's crazy expensive, but it definitely doesn't strike me as the bargain that many people make it out to be.
What lenses are we comparing this with besides the Canon 1.2? Just a thought i'm having, I know the 50mm 1.4 Canon is old and poorly regarded but literally nobody is comparing these two lenses.
I had the old Sigma 50mm 1.4, and I LOVED it, the bokeh was awesome, and it was really sharp(I did have to return my first copy as it was very softttt.) But that lens was $400 new and worked fantastic for me for a couple years.
Is the new Sigma really twice as good as the old one?
The problem with the canon f/1.2 is that it was sharp enough in the middle... so if you follow the rule of thirds... then you are probably cropping a good deal after the fact. Also... to have the lens be sharp, you had to stop down to around f/2.8 or so. Yes it has a magic bokeh per reports... but I'm not going to go into that.
Then you have the sigma... which is sharp wide open giving you an addition 2 stops of light. It may or may not have a magic bokeh yet... that remains to be seen... and no other lens in this price range or lower can quite compete with the color/contrast/sharpness/and distortion that the sigma is bringing to the table except for the $4000 otus... which after tax, let's say it is $4240.
So far the only critiques of the lens is that there is some manageable chromatic abberation, it is a touch heavy, and it doesn't have IS.
I contend that you really don't need IS if you are shooting at 50mm, f1.4, and with the current batch of canon full frame sensors 6400 iso is quite usable. It isn't quite night vision... but it is solid.
As for being heavy... then go out and buy a 50mm f/1.8 mkii... it is light and it is widely mediocre... well... it is good for the money, but it feels like a toy and there are more than a few that say it fell apart in their hands.