frontend proxy really useful?

[Chris Nokleberg]

I was rereading

  http://perl.apache.org/guide/scenario.html#Buffering_Feature

and was surprised to find:

  "Therefore if you don't use mod_proxy and mod_perl send its data
   directly to the client, and you have a big socket buffer, the
   mod_perl process will be released as soon as the last chunk of data
   will enter the buffer. Just like with mod_proxy, OS will worry to
   complete the data transfer."

Is there any new information on whether this is the case? If it is, does
it make the light frontend buffering proxy technique useless as long as
your pages fit in the socket buffer size (256K on Solaris)? (assuming the
proxy is just a dumb passthrough to one backend server)

Thanks,
Chris