Though I've had this lens for a while now, I haven't really used it much as I got I just before I sold the D700. It doesn't really suit the D90 I have now due to lack of manual focus lens metering, but I decided to do a test anyway, and adjust exposure off the screen. Like most fast aperture portrait lenses, it lacks a bit of contrast and sharpness wide open, but by f2.8 it is pin sharp. This is a very similar proposition to the Nikkor 85mm f1.4 Ai-S I also have, and common for fast portrait primes. Like the 85mm f1.4 it shares the beautiful bokeh in the out of focus areas at wide open aperture.
In fact it is the lovely wide open bokeh that makes purchasing lenses such as this worthwhile. They're really not that sharp until f2.8 or f4, and the longer minimal focal distance rules out any semi-macro usage. A similar focal length macro will ultimately be sharper, but the photos won't be as creamy.