Performance difference between if(!-e) and try_files?

[Michael Shadle]

I am trying to generate a following in getting a small modification
added to Drupal that would allow it to work with try_files, as it
doesn't right now (full explanation here:
http://drupal.org/node/827236)

I am wondering though, exactly how many syscalls or savings per
request you get from using try_files instead of if (!-e
$request_filename) ? It would be interesting to be able to reference
some numbers, and I don't trust my debugging skills to get it right.
Igor, you probably know how many each one makes in your sleep... :)
would you have any ideas?