I am in law school also (about to finish in may) and I have been using a few HCs...I love them. I have never had any problems with them and I don't even care if they get dirty since they aren't really that expensive. Also, at my school, they aren't that prevalent, so I don't feel like I am carrying a "trendy" bag or like I am seeing my "bag twin" everywhere I look.
I don't own any longchamp bags...but I do see them all over the place. It wouldn't deter me from purchasing one, but at this point (1 month until graduation) I don't really need to invest in any more nylon bags anyway, so they aren't even on my radar.