I want an 85mm prime lens. It could be 100mm, but no more. Nothing out there is pushing my buttons. But I have hope that Canon will bring us a new version of their 85 f1.8 with better corrected optics and IS. Sell it in the $500-600 range like their revised 24 and 35mm lenses and watch them fly out the door.
I've looked hard at what's currently available and IMO there is a strong case for this lens.
Current Canon 85 f1.8:
Not that sharp wide open and lots of chroma (purple and green) under some conditions. I had this lens before and consider it a good lens, not great.
Canon 85 f1.2:
Too expensive, too large and heavy, slow focusing, and I don't need my 85 to be that fast. f1.8-2.0 is fine thanks.
Sigma 85 f1.4
Again large and somewhat expensive, although not too bad. I desire compatibility and reliable focusing over the extra lens speed and, maybe, slightly improved optics this lens promises. The idea of having to use Sigma's proprietary software to dial in focus combined with the thin DOF f1.4 affords add up to more trouble than I care to deal with.
Canon 100 f2.8 IS macro:
Nice lens but not fast enough for my purposes. It is also quite large and heavy. IS is nice though as well as the macro ability.
Rokinon and their kind:
I want AF. I also suspect these lenses are fragile and become de-centered easily if not babied. I know some really like these but the one I had was not good and sent it back.
No AF. Bummer.
So Canon, bring us the updated EF85 f1.8 with IS and modern optics. If it's in the same league as the 35mm f2 IS, I'll be thrilled.