Works right away and is easy to configure, the documentation is a little light, but since its pretty intuitive thats not a real problem.
Upon purchase I discovered it is was also:
Very easy to get up and running.
Intuitive enough for non techies to use without training (I can't keep them off it).
Pretty, a number of good looking templates were available.
...and that was before we talk about support, if your site is anything like mine you will have a number of 3rd party extensions running, and reality is when you want to seamlessly integrate a major component such as a blog not all these disparate parts will play nicely together. I had a few teething issues, nothing major, but small things that annoyed me (even though the public may not notice), the Easyblog team could not have been more helpful or responsive, in a matter of an hour or so, all my issues were satisfactorily addressed, even if the cause of some of them did not lie with Easyblog, I have paid a lot more for much worse customer service. For this reason alone, if your serious about your website, Easyblog really is an excellent choice.