I manage a small hosting company and I can tell you right now, stay the heck away from Joomla. It is a quick ticket to being hacked.
One of our clients put it on our box and we have had nothing but trouble from their sites since. Twice the ISP has threatened us with a 24 hour shutdown notice due to the clients Joomla being hacked and attacking other sites.

While Joomla can do some nice things, it is not worth the hassles.

If you do use Joomla, then like Wordpress, stay on top of the updates. Patch often!

The problem a lot of people make is they install wordpress or joomla and then set and forget it.