IIS7 is really like taking the best of Apache and best of IIS6, and putting into a well-working server. If you want IIS7 to be even more Apache-like, then there are a couple of low-resource plugins that will do it (add .htaccess support or cache FastCGI PHP, for example).
Linus is open source (not to be confused with "free", because it's not free to operate), often requires less resources, and is in more widespread use to small clients and individuals. That's really all it has going for it. Outdated ideas like "more secure, more stable" etc haven't been true for several years now.
It also helps to use a good Windows host that knows Windows. This is why I use EuroVPS for all of my Windows hosting needs. -- they're quite excellent at it.