I am a Round 2 admit. Here is my interview experience… Hope it helps people in R3 and R4….
My first interviewer was from a business family. The interview was it his residence. I gave him my CV at the start of the interview. The meeting started with him explaining me how the process will work. He would ask me questions for first 25 minutes and then I will have 15 minutes to ask questions about the school and his experience. The questions were all very straight forward… Why MBA, Why INSEAD, Why now… Then we discussed about my job and leadership experience. I don’t have too much of experience outside India, so one of the questions was how will I adapt with so many different nationalities/cultures at INSEAD… This took me some time convincing him but it was a good discussion… I gave examples from both my experience with different cultures in India and abroad and how I had adapted….. I felt this was a critical question for me because after this he said I am done with my questions now your turn….. He kept writing in a notebook till this point. I was aware that till this point I was the one who had done all the talking so I really wanted the interviewer to share his experience, his motivations… Slowly the atmosphere became more informal and we discussed pubs culture in India, travel in Europe for students from INSEAD… Discussion was around 40-45 minutes…Overall it was a very pleasant interaction….
The second interviewer was an entrepreneur running an Entertainment firm. This interview was at his office. I must say it was the most free-flowing discussion I have ever had. He didn’t want a CV or any document. It just started off as a discussion about my life and I felt the guy was genuinely interested in understanding my motivations. I really felt free and completely opened up about my strengths, weaknesses, successes and failures. It could have been risky but I just didn’t want the flow to be broken by me thinking and speaking. Later the interviewer talked about his experience at INSEAD and how he had really gained from the experience. He said he had gone into the program completely convinced that he wants to be into Investment Banking, had an offer in hand but finally ended up deciding to do his own thing and it was all because of the confidence and exposure he got at INSEAD. We ended up discussing family, entertainment business and growth of e-commerce in India. All together the discussion went for 1.5 hours and I was very happy that I was able to experience it….
Apart from what all the other interview experiences say I believe the key is that the interviewer is able to see you as a classmate….I think that is one thing they try to judge… That doesn’t mean getting too friendly with them initially…Rather be professional and formal... Tell your story but look for opportunities to subtly make the interaction informal…
Apologies for the post being lengthy but hope it helps….

Regards
Amit