Less than 20 years ago, Windows was the hobby level OS compared to Solaris and AIX. Windows Server 2005 was a complete and utter joke compared to Solaris. The company I worked for in 2006 was moving their Solaris servers to Linux. Windows wasn't an option because it wouldn't even meet the specs in real life.
I think you may thinking of Windows Server 2003. I also suspect you've never run Windows Server 2003 at enterprise scale either. No operating system is perfect, but Windows 2003 was a reasonably capable workhorse, even in 2003.
My old company made a DIS box (UK gov-specified integration server that would talk to the central Government Gateway) as Java on Solaris in the early noughties, and doing a performance test that one Solaris machine took down the entire Windows-based Government Gateway test environment. Draw your own conclusions :)
It's difficult to draw any conclusions without knowing the environments, what's running on them, were they configured properly, etc etc.
Don't get me wrong, I'm not ideologically bound to any platform, but stuff like this just sounds like another tired old-man Windows vs Linux/Unix pissing contest.
