I don't think there's that much of a difference, it's really about how well you perform in front of a panel vs. individuals. For the panel, you don't have to have as many questions prepared, which could definitely be a plus for some 😉 More interviews = more diversity for questions they ask of you but that can go either way. But I think the main point is that there are three different people submitting their evaluations of you, and that's all that really matters in their evaluation.
Also, since people keep asking (and probably still will keep asking...oh well), again, people interviewed in January and February last year and got Chicago. There are usually places open throughout the process to get an even class but I suppose it depends on who happens to be holding and withdrawing from their spot too once it gets really late, like into March or so.