<p>For those of you familiar with <a href="http://www.gallio.org" rel="noreferrer">Gallio</a>, what Advantages and Disadvantages have you experienced using this tool, a so-called Test Automation Platform?</p>

On the advantages front, integration with everything is quite nice :)  Seriously, I'm a huge fan of the experimental integration with Visual Studio Team System (screenshots
here
). I think that really lowers the bar for those new to unit testing.
The only disadvantage from my perspective
so far
is the fact that it isn't released yet.