I actually just recently started working with Kaplan. I had to apply on their website. I was not "sought after" by them.
They do hold a strict rule that regardless of what you're teaching, you must have received a 90% or above on the exam. That's not in every area, but overall.
The pay is good when you're TEACHING. However, when your preparing for lessons or training (you need to train and PASS training before you can get a class) the pay is minimum wage. At least that's how it is for me.
I would say its definitely worth it if you plan on tutoring for a while. That way, towards the end, you don't have to really prepare for lessons anymore and can just teach multiple courses at the same time and thus really rack in some serious dough. However, Kaplan doesn't allow you to teach multiple courses until after you successfully completed your first one. So if you take that into consideration, as well as the 5 week training period, it might not pay to work there for, say, just one summer or something.