I think it's primarily due to the PR the school has received because of the rise in rank.
Well if you have family there then I think you should do alright if you do some legwork (i.e., mass mail). I haven't really seen much of a difference in perception. All of the attorneys I knew prior to entering law school all knew that it was a very good school and encouraged me to go and that continued when I was interviewing. I think I came into the fold too late to experience the difference in perception. What I did find interesting was that the older WashU alum that I interviewed with were all a little bitter that they didn't get to take advantage of the ranking and facilities when they were in school. I don't necessarily think it was a negative but almost uniformly came up in the interview.
Off the top of my head:Best: Great facilities, lots of commitment to make the school top notch (i.e., they don't mind spending money on salaries, staff, scholarships, etc.), VERY laid back student body, relatively strong national placement compared to lower ranked schools.Worst: Career services not proactive in helping those who don't get jobs out of OCI (it's still relatively to get a job but the CSO office isn't very helpful), relatively weak national placement compared to higher ranked schools especially in the West and Southeast, St. Louis legal community not too supportive of the school (they almost consider the students carpetbaggers and prefer SLU and Mizzou students for the most part).