A student must complete at least two reviews before a mentor can graduate or fail them. However, many mentors will work with students on more than two. It really depends on the student and mentor. Personally, I tell students when I think they are ready to graduate and leave the option up to the student if they want to continue.

There are many different ways to pick a mentor. Typically, it's either based on a style you want to emulate or specific toy expertise. My feeling is that style is more important than toy expertise because a good mentor can help a student with any product type.

What I would suggest is sending a private message to a mentor that you are interested in working with and explain what you hope to gain from the class and what your expectations are. That way you can be sure that the two of you are compatible.

Here is a thread that discusses the program from the student's perspective: link

In general, I would say you can't go wrong with any mentor because we are all different and have something different to offer. Good luck!