I don't think that it really matters if you are interviewing for a waitlist spot. They take a lot of people from the wait list.
I really liked Creighton. The interview day was laid back and relaxed. They tried really hard to make the day comfortable. Though you are naturally being evaluated, they spent the day showing me why I want to go there. The sutdents M1-M4 all really seemed to love it there. They were just happy.
I was accepted to Creighton in mid-December. At that time I canceled my upcoming interviews and withdrew my applications at most of the remaining schools left. Since I was rejected by Iowa, my former number ! choice, it is highly probably that I will be in Omaha next year. I am excited about this.
I think that Creighton is looking for students that fit into their mold: clinically oriented students who will fit in with the tight knit group of existing students. Be able to answer "why Creighton" with thought out answers and be able to talk about your volunteering and service. I talked about the fact that I have many relatives in Western Iowa and would like to be closer to them.
Good luck. If you have questions post them here or PM me.