If your goal is to convince people to switch to mod_perl, I don't think
this will work very well. People choose platforms for practical
reasons, the most common being that they already have employees who know
that platform. Relative ease of parsing a form has little to do with
it, especially since that sort of thing is easy on basically every
platform now.
Additionally, comparing mod_perl to PHP/JSP is apples to oranges. If anything, people need to understand that mod_perl != CGI != markup languages. The more you compare them, the more you get of "mod_perl is losing to PHP!", which doesn't make sense, and works against mp. I'd like to see less of this and more education about mp and the Apache API.