Very personable and enjoyable conversation. He will try to catch you off guard and stump once or twice. But most of it is just general discussing particulars.
The owner portrays that he is more interested in the person than their skills. This is a bit of a red herring though, he's still more interested in skills. That said, being that the owner is a developer it feels more like talking to a colleague than a boss and it is definitely a more enjoyable experience than talking to HR. I imagine most who interview here enjoy the experience regardless of the outcome.