I moved to Nginx from Apache about 6 months ago and havn’t looked back since. My Goal was to install a web server for my wordpress sites which is fast, light and easy to configure.
The only draw back of Nginx is that it does not support DSO or Loading Modules dynamically like Apache.
This is not a problem if you want to install and run only WordPress, but it is a problem if you want to install external modules like Google’s pagespeed without having to recompile nginx.
The Solution I propose was to use Lighthttpd, which was event driven, similar to Nginx and lighter but instead I came across Tengine on the Google pagespeed documentation page.