Wincent.org, despite recently learning the difference between a "notice of infringement" and a "cease and desist" order, has posted an interesting article on how some of the more recent OS X builds are stacking up on the networking front. According to Wincent.org:
Many articles on the web about the recent builds of MacOS X have focused on how it feels to perform. How fast the dock feels, and how fast and smoothly it moves around windows. Since I know network speed is very important to many people who work with large files in a workgroup, I decided to try one of the newest builds, MacOS X 4k60, and compare the networking speeds to MacOS 9.1.
You can find the full article, along with a wealth of other OS X information, at the Wincent.org Web site.