Perl vs PHP isn't anything like PostgreSQL vs MySQL -- that's a totally different, and warranted, argument. MySQL is victim of massive hyping that gets new users to take MySQL on as their "database" but gets them in trouble down the road when they start trying to use MySQL to build medium to large applications or to store mission critical data in a very unstable "database".. It's horrible shortcomings are never mentioned to inexperienced users, causing them to step into something misinformed and unprepared for what can happen due to MySQL design, or lack thereof. I'm not bashing MySQL for no reason, I was once a MySQL user until the hype faded away and the true nature of this so-called RDBMS reared it's ugly head.. Bottom line here is that MySQL has it's uses, it's not and appears it will never be, a RDBMS so if you need a realy database and not just a SQL interface to a filesystem -- use something other than MySQL.
The Perl vs PHP argument, in my opnion, isn't a valid one. Both Perl and PHP can do what needs to be done, Perl is a more complete programmming language but that's because it wasn't designed to be just a web programming language like PHP was. If you need more out of a language, go with Perl but expect to spend many times the hours learning it as you will learning PHP. I speak from experience in this area as well.
I use PHP because Perl is cryptic and seemingly bloated (though PHP can be too at times) -- it comes down to I like PHP, so I use it and I suggest anyone else do the same (Use what you like that is).
