I've been watching this thread but staying out of it because I shoot FX and your profile indicates DX. Plus I haven't really seen how you intend to use the lens so I'm going to assume classical portraiture. I'm glad Brian added the technical details because I think the 85mm f/1.8 AFS is a great addition in the right situations.
I used the 85mm f/1.8 AFD on a D200 and decided the focal length didn't suit me on a DX camera. I found that the shorter end of my 70-200mm f/2.8 AFS actually produced better portrait results, but that lens is intimidating for most subjects.
I recently added the 85mm f/1.8 AFS to my FX D700 and find it to be a good match and I like it's rendering. I've used it occasionally on my DX D2Hs, but I still find it a bit awkward focal length for my preference.
So much for that, have you thought about whether you will use the lens at it's f/1.4-f/2.0 sweet spot? At f/1.4 the lens is very critical about it's focus point. Much of that incredible bokeh you see illustrated comes from FX cameras at those apertures.
My first experience with the f/1.4 AFD was on a DX camera. The results were excellent. However, to achieve that bokeh I had to "extend" the subject to background distance and with the 125mm effective FOV, I just plain ran out of room in my typical shooting venues before I could reliably get that look.
The suggestion to try one in your actual shooting situation is likely your best bet.
Just another thought.
Roger It's still, ISO, aperture and shutter-speed, right?