mod_php issues with security or stablility?

Hello, I work for a large web hosting company and we currently use php.cgi. We are considering changing to use mod_php. Is anyone aware of any security issues with using mod_php? Are there any stability issues? Theoretically, could a customer write php code that could crash Apache? Any other pros or cons to mod_php vs. php.cgi? We have been using php as a cgi for many years and no one seems to remember why we starting running it as a cgi rather than an Apache module. Thanks, Lane