> I trust Apache to spin up a new PHP process for each request. Except under DOS attack or with some horrendous memory leak, it's just solid. Obviously it's a lot more overhead.

FWIW, PHP-FPM has been the standard way of deploying PHP in production for many years now [1]. No need for running PHP as an Apache module.

[1] https://cwiki.apache.org/confluence/display/httpd/PHP-FPM