Re: 6 Directions
The drawback is the IP training methods apparently take a lot of time and effort, though it seems like it sucks you in when you start doing it.
Some people are "sucked in" simply because they are amazed at what these skills can do to enhance whatever martial art they're training in. When you find a better way of doing something, why would you not embrace it?
With a good teacher, an individual who already has grounding in an MA, and sticks to regular IP training, can gain some basic usable skills within a couple of years. If your livelihood depends on cage matches yesterday and tomorrow, that's probably not practical, but since MAs realistically are a hobby for most, unless you're a professional LEO, etc., it requires no greater time investment than that required to excel or to at least get proficient in any martial discipline.