Maybe it's just me but I couldn't help but feel that the only reason why I was brought into the interview was because I had, in the past, worked for one of their competitors. A lot of the questions centered on the business structure and key decision making process of their competitor (my old work place) rather than my actual experience. I didn't give much away as I felt that it would be unethical for me to do so. They also asked for details on the people involved in specific business functions in my old work place, functions which they were looking to expand upon. But again, maybe it's just me.
HR and the line manager were very pleasant though.