I had a 30 minute on-campus interview and within a few days was asked to join the company for a Super Day the next week. The on campus interview was a case very similar to the one kept on their website, market sizing. The Super Day consisted of 4-5 interviews that were each 30 or 40 minutes long, depending on the level of employee who was interviewing you. They were all fairly similar and included behavioral and case components. Everyone was generally very nice. There is also a presentation either before or after your interviews (depending on if you join for a morning or afternoon session) about the company. It was part of why I wanted to work for them so badly.