I've used Joomla 1.5 for one website. I have first watched a video tutorial, without this, I think, I would have had big problems starting with Joomla, it's really very complex. You must always think, how the different parts of the site are connected with each other. So for example where to hide the pdf icon and so on.
In the opposite WebsiteBaker is really simple to use. WebsiteBaker was my first CMS and I still love. I'm always testing other CMS, but I always return to WB.
In Joomla there are more functions and addons, and for a big and more complex Website it is better than WebsiteBaker, I think. But when you have to build smaller sites, like for a small company that wants to present itself in the internet or for an association, WebsiteBaker is simply perfect.
I never thought that it is so easy to build a template with WebsiteBaker. Now I'm creating all the templates by myself.
The only disadvantage is, that there could be more extensions. Or from the other side: I should learn php and mysql better, so I could create some by myself.