Rick,I interviewed with both firms last year and I really don't think there are any surprises if you've done your homework - it's a pretty transparent process. Case studies, 'social' interviews, the odd roleplay and teamwork exercises, numeracy tests, and psychometric tests.I ended up with a bunch of offers and went for Mercer MC - a nice crowd, good work/life balance, and a strong offer in terms of pay. If you've any questions about it post an e-mail adress and I'll get in touch.Good luck with the interviews!