Having owned the legendary AF-D version of this lens, it seemed hard to imagine that there could be much improvement in an AF-S version. However, having now upgraded I can confirm that this AF-S version represents a noticeable step forward. Whether this step up is enough to justify the extremely high price may be a different matter..!
As an 85mm f1.4 lens, this optic shares the almost unparalleled ability of its predecessor to isolate subjects at medium distances, which is why photographers have always loved Nikon's 85mm f1.4 lenses. Personally I think that the levels of sharpness, contrast and saturation are now noticeably better than the AF-D version and have been astonished by the quality of some of the images I have taken with this newer lens.
The other major benefit I have found is the autofocus speed. Although acquiring focus was always brisk on the 85mm f1.4 AF-D, it did still rely on the `screwdriver blade' system. When shooting motorsport or other high speed subjects, I would often pass over this lens in favour of newer AF-S lenses such as the 70-200 f2.8 AF-S VR lens.
With the new AF-S version I never have any such concerns as focus is blisteringly fast: it's actually very hard to get the lens to go out of focus for long enough to notice!
I am delighted with the upgrade as it now allows me to use the classic Nikon 85mm f1.4 prime lens design with any subject, no matter how speedy. Portraiture is the obvious forte of this lens but I have found all manner of other uses for it, particularly in shooting sports or action shots where it can `snatch a subject out of the background' in the blink of an eye to produce very impressive results.
Similar in shape to the AF-D version, this lens is slightly larger but remains a nicely balanced lens on any of the larger Nikon D-SLR bodies.
The only possible down side to this spectacular lens is the very high price. If you already have the AF-D version and are rarely bothered by the focus speed, then it may be hard to justify the substantial price. If you are new to the world of Nikon 85mm f1.4 and are struggling to justify the price of the AF-S version, then a secondhand AF-D version will give you 85% of the quality at a much lower price, albeit with slower focusing.
It's interesting to see that the introduction of this lens has not really generated a flood of secondhand 85mm f1.4 AF-D lenses on the market. Presumably many portrait photographers are happy with the superb abilities of the older lens. At the end of the day, the price of this lens may be the major factor in deciding whether to purchase it or not... :-)