I really enjoyed interviewing at Virginia Mason. The residents and attendings there seemed really friendly and I spent the day in scrubs wandering around the OR. It did seem a little more scripted though, and our "host" for the day was one of the attendings, not a resident. However, he was really nice and had gone through our CVs and personal statements and actually knew stuff about us. It seemed like a tight-knit family there.
UW was more impersonal and didn't really impress me that much. The residents didn't seem that happy for the most part, and almost all of the ones I met had transferred from other specialties. Of course, this was my last interview (of 30) and I think my view of UW was colored by the fact that I was just really tired and I wanted to go home.