I agree with the comments about selection bias amongs the residents who volunteer for these residency dinners.
I will say this,though: residents have a vested interest in ensuring that people who come to their residency really
want to be there. You may have some PDs who care about board scores and pedigrees, but most residents couldn't give a $hit about any of that. Most of us want to know:
[*]Can I count on you?
[*]Will you still be fun to be around after a 16 hour shift?
[*]Will I learn anything from you?
While I think it's very awkward and difficult to ask pointed questions during the interview day, I think you can do it over a beer or chow at a residency dinner. And while you won't be meeting the dissatisfied burnouts, I think most folks who show up will be fairly candid about what to expect at the program. I have. It's in my best interest that people rank my program appropriately.