But I'll never part from the 85Lii
Funny. Different strokes for different folks, as the 85/1.4 Nikon is another reason I'd consider a switch... The ergonomics of the 85/1.2, which I own, are silly. If you take the lens off extended, you can't un-extend it, since it needs to power the motor to retract. Watch out for that rear glass element that sticks all the way out; you don't want to scratch it/hit it as you're mounting it to your body.
Furthermore, the CA on the sides is bad enough to make even in-focus objects on the sides appear soft. Then the 8-blade aperture means that out of focus highlights are no longer a pleasing circle at apertures smaller than f/1.6 (yes-- they're only really circular at f/1.2-f/1.4). Canon knows 9-blades is the way to go -- something they updated in their new 24-70 zoom. It gives you more circular OOF highlights AND 18 point sunstars... seems win-win to me. Yet all their professional primes only have 8-blades.
At f/1.2 though, it does let in a LOT of light. For any given f-stop, it actually appears to let in 1/3 stop more light than any equivalent aperture on the Sigma 85/1.4. Also has shallower DOF for any given f-stop than the Sigma, hinting at the possibility that it actually just opens up wider at any given f-stop in comparison to the Sigma. These are really its only redeeming factors, IMHO. But it is in sore need of an update.