RoR in Windows Server 2003.. Is there any problem?

Hello,

I'm currently wirking in my first commercial project with RoR. The
client is asking me if we can use Windows Server 2003 or Windows 2000,
because he has 3 application running on 3 virtual private servers
running Windows, and he thinks that the most efficient way to go for
this new application in RoR would be to create a new virtual private
server in that big computer.

I'm currently developing applications with RoR in Win XP, using the
last version of InstantRails, and everything seems to work fine, so I
told him that I was going to investigate, and give him an advice.

Now, I did just that, and I found in this group some posts discusing
this issue. The conclusion is that you can run RoR on Windows, but
everyone still prefer to run it on Linux. Then, my question is... why?
Is it really better to run RoR in Linux/Apache/Mongrel than
Windows/Apache/Mongrel (for example)?

Any comments would be appreciated.

Thanks!
Federico F.