Is this same phenomenon also empirically true for ki-development, i.e. the yudansha of the ki-society really can demonstrate peng-jin, fa-jin, etc?
Which art is most appropriate for which kind of person? What are the relative merits of Ki-Aikido vs internal CMA?
If you're after fa-jing etc then the obvious place to go is Taiji. Both Taiji and ki-aikido will get you a good start on the way I'd say, having done both that both have plenty of stuff to teach and if you get a good start in one it will inform your study of the other. Doesn't mean ki aikido people can't do Fa-jing mind, just that they might not have a word for it, so go find the people who do have a word for it if you want what that word is supposed to be. One of my sempai does both Taiji and ki aikido and finds them equally informative and worthwhile. As far as he's concerned they are the same but different (in emphasis mainly). You shouldn't need to go to a Taiji class to make your aikido work IMO as the internal skills should be in aikido anyway (discussions as to whether they actually are or not should be left to one side for the present, suffice to say I think they should be and that they are in all good aikido I have ever seen IMO)
For myself I prefer ki-aikido, but that's just me and is largely to do with both my opinion of my aikido teacher (i.e. I don't think I've seen a Taiji or CMA teacher who can do what he does, this of course doesn't mean they don't exist, simply that I personally haven't seen them) and also my preference for the aikido waza over Taichi techniques.
I've had this discussion a number of times offline and usually it just degrades into a Chinese is better than Japanese argument, with the Chinese side insisting that everything good in Japanese MA came from China and the Japanese side telling the Chinese side they're wrong. Hopefully this won't happen in this thread. But it would be an interesting discussion to pick certain aspects of each of these internal arts and compare and contrast. I suspect they both are actually very similar in scope and depth and looking at both would be a worthy topic of conversation.
Fa-jing is the obvious starting point to my mind. Here's a question. How would one apply fa-jing to aikido waza and is it strictly necessary for them to be effectively executed? Note I'm not talking about Daito Ryu and my broad distinction between the two (DRJJ and Aikido) is that DRJJ tends to draw opponents in and aikido tends to throw them away. So you could probably re-phrase the question as: Is fa-jing (or similar) needed to effectively throw an opponent away from you? Especially if they are attacking with force and committment (force and committement issue might be best treated as a slightly different aspect of the same discussion)
PS - Yes, computer is doing simulations again for the next day or so, so lots of free time, prob not always a good thing......