Looking for *good* Unix Linux Windows Comparison

Hi,
I have a test in few days. One of the topics that is likely to come up is a comparison of operating systems such as Unix vs NT.
I have been looking on the web and am finding it difficult to find a comparison is both objective (not sponsored by Microsoft or written by somebody rabidly ant-Microsoft) and that gives valid metrics (e.g.; when Unix is described as more scalable what exactly were the criteria used? and can one read them?)

The lecturer has already stated that he is not interested in what we feel, more what we can prove.

I'm looking for something reasonably professional but free. I believe Gartner group did a piece in 2000 on NT vs Unix, but can't find it anywhere
Cheers,
Jack