Overall I found that the process, while interesting and thorough, lacked a respect for the candidate.
Phone screen - straightforward synopsis of the job and probing into my experience
3 personality tests (Meyers Briggs and two others) before coming into office interview
First round - three 2:1
Second round - two/three 2:1
Final - panel presentation and 1:1
During one of my first round nterviews, one of my interviewers sat with his feet up on the desk in front of me (i.e. - my eye contact was with the soles of his feet, not his eyes) while the other left the room twice to get a snack. I was so put off by the attitudes that when called back in for a final round, I was hesitant to even go. While at my second round interviews, I saw an employee in tears complaining to one of her collegues about lack of respect and constant negativity.
At my final visit, I was told that my feedback from all my previous interviews was stellar except for one and gave me that feedback. I was then told that this was their way of giving me one a chance to redeem myself through a presentation. They left me in the room to prepare it and then came back in. We proceeded with the presentation, after which I was asked what I learned from the process and how I expected to grow from it. They explained this was their general approach to their employees and asked how I'd feel about working in an environment like that.
I left the interview, called the headhunter who had set it up and explained that I really hoped they would not offer it to me. Thankfully, they came back to him with the feedback that they didn't sense I really wanted it. Now that was an accurate assessment.