First interview
Who: Mid 30s entrepeneur working at startup.
Interview: Met at a restaurant for lunch in London, interviewer was extremely warm and friendly. Brought a copy of my resume and asked me to walk him through it with occasional follow-up questions. Then asked the usual: Why MBA? Why now? Why INSEAD? Then went into detail on some activities and his experience at INSEAD. Only tricky part was interviewer identified the biggest weakness on my app was lack of experience and drilled down into it. Very relaxed and informal.
Second interview
Who: Mid 50s investment banker running his own hedge fund
Interview: Met at hotel in London for a drink. Quick overview of my background and then the usual about why INSEAD, why MBA, why now. Was really pressed about why not an American school as they have a lot of the attributes I described but interview seemed convinced by responses. After the typical b-school interview questions there was 30-40 minutes on other shared interests and then interviewer told me he would strongly recommend me and wished me the best.
As most posts have stated, walk me through your resume, why INSEAD, why MBA, and why now have to be down cold, seems like every other question is based off of your responses.
Result: Admitted.
Good luck!