Hmmm.... Seems like in Internal Medicine in some places it's become an expected thing to do a second look, to show that you're interested. But I've never seen this mentioned for Anesthesia. Most residency programs I interviewed at said it's strictly for you, as they already have enough information to decide how to rank you.
I'm not doing second looks. There are a couple of programs that I'm not sure how to rank, that I think would be useful to do second looks at. However, with the travel and my current schedule, it's not reasonable to do, so I'm just sucking it up and deciding without the second look.