Of the three, Hamline would have to pay me the most to attend.
UST is an up-and-comer. That school has a ton of money, and seems very intent on improving its law school. They've been very aggressive in luring quality faculty and students from more established schools.
My impression is that William Mitchell has a good reputation in the area. It's been around for a long time, and nobody I've talked to has bad things to say about it (at least no MN lawywers do. Kids in online forums have bad things to say about everything). WM is, from what I've gathered, very focused on teaching practical lawyering skills.
Hamline used to be good, but it has been in decline for a few decades now(in law and other areas). My impression is that most of its reputation is based on people aged 55+ remembering how good it was when they were applying to school.
Given equal money, I would choose between UST and William Mitchell. I would probably lean UST, just because I think they are likely to keep investing in the school, and I am more of a theory guy than a practical skills guy. That said, were I in this situation, a big scholarship from Hamline might get me to reconsider.