Although I didn't make it to the selections, I was very much pleased to be a part of the process. Professionalism is one thing we look for, while meeting a person or going for an interview - and the entire interview process was very professional. The HR was extremely learned and professional. The interview process was a day long. There was a PST followed by an initial guesstimate round, post which candidates are segregated.
After this, the in-person rounds begin. There are 3 rounds in there, first being a Guesstimate, second a case study and third an HR Interview. Each of the processes are 1 hour long, and are extremely standard. You can expect some difficult questions, but they test your skills to determine if you're a fit to be a consultant in the first place, let alone be an employee. They also have interview feedback, to let the candidate know about their strengths and weaknesses, which is very rare to find.
Overall, if you wish to be a consultant, you'll find their process very much up to your expectations.