I have the 85 1.4.
I hired the 85 f2 to see if it would do what I wanted, which it did, except I wasn't really very happy with the softness.
That isn't really a technical term, but it was what it seemed like compared to my 105 f2.5.
A friend came around with his 85 1.4 and we had them on side by side tripods. Just looking through the viewfinder one could see a lower contrast picture through the F2 lens. I decided to wait and save up for the 1.4 and I'm happy that I did.
You will as Nige says, be happier with an F2 in the bag, as opposed to a 1.4 on the store shelf. Depends what you wish to use it for. The 1.4 uses 72mm filters, that may be an issue.
I have just come back from a dry run in a Church for a wedding I'm shooting tomorrow. I am using the 84 1.4 because the place is so dark, even with the lights on, that I need every bit of light gathering power I can get, to focus.
The following is quoted from my Nikon Compendium, Handbook of the Nikon System, by Rudolf Hillebrand and Hans-Joachim Hauschild, pages 131 - 132.
" In 1977 a newly designed five element lens with a maximum aperture of f/2 appeared as a successor of the 85 f1/8 six element design released in 1964. A great lens matched to the portrait photographer's demands by it's intentionally reduced contrast: skin blemishes and wrinkles should not be too obvious. On the other hand this lens is not that well suited for on-the-spot photography where the full aperture is often used, as well as high speed films delivering low contrast themselves. The desired crisp sharpness is simply missing in those shots, but together with the contrasty Kodochrome 25 it demonstrates its high resolution.
In 1981 a real on-the-spot lens finally appeared in this area, the Nikkor 85mm,f/1.4. The use of CRC made it possible to do without an expensive aspherical front element, but even so this super-fast lens delivered brilliant, contrasty negatives and slides at any aperture. Slight losses in terms of distortion and vignetting do have to be taken into consideration though, and a lens as fast as this cannot be equally well-suited for close-range shots."