If speed is of absolute concern,
pick SCGI over Unix sockets and use
httpd.
If interoperability of your application stack for
diagnostics or any other purpose is of absolute
concern, pick HTTP with TCP sockets.
If securing your application stack from other
software in your infrastructure is of absolute concern,
and your application and web server run on the same host,
pick anything with Unix sockets.
Otherwise, you'll need to consider the pros and
cons on the previous pages with your particular application
deployment in mind.