I got an hourly preparation service for mock-up interview with Greg and found it very useful for my upcoming interview with HSB and GSB. The good things were:
1) very close to the real experience the type of questions Greg asked and similar pace to the real interview;
2) thorough feedback and detailed analysis of the performance with comments on both verbal and emotional performance, as well as specific wording and stylistic element;
3) willingness to spend the time to cover everything I had concern with.
I would mention Greg balance of friendliness and professionalism, which created perfect atmosphere for the mock-up interview.