The evening event was pretty low key. I am not sure if anyone will post that they missed the event, but there was around 36 interviewees on the first date and from eyeballing the room I would say that almost all of them were probably there (but it was such an early date that I dont imagine anyone would have had a conflict). Since I am in the same boat as you, I do not know if it has any impact at all on your eventual ranking with their program. However, the formal part of the evening is more a meet & greet with faculty and residents, and I would be impressed with any individual who could meet 36 anxiously smiling faces and remember a darn thing about them that would effect their rank. On the flip side, during the part of the evening at the bar (which went relatively late - we saw the Pistons/Pacers brawl live) there was a lot more time to get to know the residents (I dont believe any faculty were present) and for them to get to know you. You could definitely show up late and still get some benefit from the event. If you are really concerned, you could call the contact person. She is very pleasant and I am sure could help you guage the importance for ranking if any. Probably the more important aspect of the evening event was getting to know everyone and getting the inside scoop in a non-threatening environment. It was nice to find out that the residents actually are not superhuman and all seemed to be good people. However, there is also a lot of time to meet the residents and faculty on the interview date. Unless you hear that it affects ranking, I personally would not burn a good interview to go to the social unless I either was sitting on a whole pile of interviews or you know that Mayo will be high on your list. I have to admit I was immensely impressed with the program and felt like Rochester could actually be a plus if you like the small town, midwest lifestyle.