The interview process was not difficult. The first interview consists of HR selling FTI and its brand to you, so no technical questions involved. The second interview with the MD is mostly a cultural fit chat. I believe there is a third stage where you meet the SMD, but I can't comment on this as I did not reach this stage. All in all, the interview process was very informal. I'm surprised they didn't test your financial modeling skills as it seems it's the norm with restructuring firms.
Also, don't bother sending follow-ups as they will not respond. Even Big 4s and other management consultancy firms will provide you with updates and feedback if you ask. I guess courtesy is not what the company values.