Hi all, a couple things that might be helpful.
1) I work with a big company, and a current Wharton Admissions Fellow just held a prep meeting for the TBD. He/she stated that the reception is really just to help you get to know people who might be in your team and doesn't play into your evaluation! My feeling based on his comments were that if you can go, do, since you'll be able to possibly form rapport with team members and thus have a better interview, but it's not worth upending your life for, since you may not even meet the folks you'll be with.
2) I had my Lauder interview. It was simple, very low-key, with a current second year student on campus, and consisted of the following typical questions:
-Walk me through your resume?
-Why Lauder?
-What's a recent cross-cultural work experience you've had?
-Do you have any questions for me?