My experience is that female interviewers are more helpful in an interview, whereas male interviewers can be less helpful and require you to prove yourself more. (I'm male, by the way.) I tend to get along better with women, and so, based on that, I would always prefer a female interviewer if I could choose. I was not accepted at my alma mater, primarily in my opinion due to interviewing with two males, or I should clarify, that I failed to prove myself as they expected. I interviewed at another similar school with two women and was accepted. They didn't sit there and say, "prove it". They were engaging and worked with me to get the answers that they wanted. I also think that cross-sex interviews can go better. Female interviewers can be harder on females.