[old_skul]

I concur with beepbeep. I use IIS on many of my sites, and Apache/Tomcat on many sites. Set up properly, either one is a good web solution. IIS catches a lot of hell because of the security issues, but then again, Apache doesn't have armies of Microsoft haters trying to hack it.

Wayne, instead of a complete platform change, have you considered identifying the problems with vBulletin? Have you updated the version of PHP on the site lately? How's the machine itself doing? Bandwidth?

Don't just shotgun the situation and create another bucket of issues to deal with.