What do you like best?
I like the fact that a freeware can actually throw you back great renders and visualizations as good as the ones you can get in +1K softwares. I also like it's compatibility, even though it's a bit limited you can use other free softwares like SketchUp or blender as a "bridge" to get really nice renders. When I was an active Kerkythea user I used to export my models from rhinos to blender and then to Kerkythea.
What do you dislike?
I dislike the fact that its interface is not really intuitive, so it takes a long time to get confortable with the software. I also dislike the fact that this software as many other freewares just don't look good. I guess it's related to the fact that it's an open software but considering its a design-related software, a little more effort on the interface should be done.
What business problems are you solving with the product? What benefits have you realized?
The benefit is basically the price, it's a decent render engine for those who are starting and just can not afford big name softwares. I actually got into Kerkythea a while a go, my boss got really impressed on first week on a new job because I was able to 3D model, render and retouch some amazing images (SketchUp/Kerkythea/TheGimp) before they even bought my software licenses.