This post is mainly for our practicing lawyer readers. If I were to venture back to a law firm, I wouldn't ask graduating students for recommendations only from their law professors. Instead, if the student was on law review (as most BigLaw applicants are) I would ask for at least one recommendation from a law professor whose article the student edited. 

First, a law professor has less reason to exaggerate or falsely praise a student at another school. Second, a law professor who has worked on an article with a student gets excellent insight into that student's attention to detail (or lack there of) and attention to deadlines (or lack there of). Third, the law professor/author gets to see the student do work where the rewards are not immediate nor as large as they can be in the studying/grades context. Fourth, the cite checking and editing work done on law review articles is more similar to the work of a junior associate than is (at least a good percentage of) course work. 

Yes, a law professor at another school will have limited interaction with that student and usually only virtual interaction. But a lot of legal work is done virtually these days; in practice, there were a number of people I worked with but never met in person. Another challenge is that law review editing is usually done by committee or by a number of students. But, especially if the student is the contact person or the responsible editor, this might show the potential employer whether the applicant can inspired and work well with his/her peers. 

I've worked with a number of law student editors. There are some who I am sure will make excellent employees, and there are others who promise to be problems.

Thinking about this more, and thinking back to my time on law review, I also think hiring committees of law schools might get some special insights by reaching out to student editors of law reviews where the law professor applicant published.