Joomla is quite...BIG is all I can say about it I have a UK developer buddy who uses exclusively Joomla and it gets the job done but sometimes it's just too much for what you may need it for. So don't box yourself in to just one CMS my tools of the trade are Joomla, Wordpress, and my own CMS for the more custom projects that the above two couldn't handle as elegantly.

So I guess in short if you need a site to do alot of things I'd go with Joomla, if you need a site where written content are going to prevail that Wordpress would be the better choice.

It all depends on what you'd want to do with it.