Is it worth the effort to make proxy and server communicate via Unix socket?

[Mikhail T.]

In a fairly common setup today, a proxy (say, Varnish) runs on the same 
system as the actual "backend" server (such as Apache).

Would it be worthwhile to alter them both to allow them to talk via a 
socket instead of via TCP (on the lo0 interface)?

Or is the win just too negligible? Thanks!

    -mi