Personally at this point, I've been most exposed to issues of correcting my "Frame" to be able to begin to access some of these skills. I am most interested in learning to capture someone's balance by absorbing their power and then feeding it back to them. Power releases are also of interest to me, but not as much.
It's sort of like a study of electricity. There are guys who do house-wiring, there are people who are into designing transformers, there are people who design Op-amps, and so forth. Sounds like different topics, but really it's all the same topic. The question is whether you should go to a vocational school and learn how to fix TV's or whether you're happier going to engineering school so that you can understand the theory that applies to everything. So I guess that while I nominally understand "different approaches", my mind doesn't work that way.... all of these *legitimate* approaches are simply variations of the same basic principles. There is only one electricity. There is only one ki/jin.