Reply to Abel: Sorry, I was referring to the "reverting to brawling" thing.
As for reverting to kickboxing, if much of your past training in full contact fighting has been in kickboxing (much of mine has), and you're trying to increase your ability in something like Hsing-I which doen't really have any kickboxing-like techniques (not like any kickboxing I've ever seen anyway), and you are trying to use only your Hsing-I techniques, then there is still a strong possibility that once your opponent puts you in danger of getting pounded on, you might revert to your kickboxing.
This isn't just a hypothetical situation. Much of my past full contact training has been boxing, kickboxing & san shou. Right now I'm trying to develop my abilities in the Hsing-I I've been training in for the past year. One of the things I've done to help make the Hsing-I more a part of myself is to fight in full contact Hsing-I matches at my school/ association's annual event.
Many people say "Why worry about whether it's Hsing-I or kickboxing, as long as it works." In a real fight, yes I agree, anything goes. But I'm already a decent fighter (well, I can defend myself pretty well). I'm not yet a decent Hsing-I practitioner, though, and my goal is to further develop my abilities in this art.
Therefore, I did not want to "revert" to kickboxing.
And I was very successful (both at sticking to my Hsing-I and at defending against my opponents, Hsing-I works very well). Peace.