DotNetNuke - Have you used this ASP.NET CMS?

So we use .NET at my job so it's good for me to play around with other .NET scripts and see how it all works.
I'm checking out this .NET CMS, this is their missions statement.

I've installed a few things but I don't really know how to get it started.
Does anyone have experience with this?
DotNetNuke - The Leading Open Source Web Content Management Framework for ASP.NET

 

Contemplated playing with it, but decided against it, doesn't look like something I could or would use.