In terms of style it does not seem to me to make much difference in the long run, though it may in the short run.
As the student progresses the sequence is from unconcious incompetence through concious incompetence, to consious competence and finally to unconcious competence.
First stage: Though he does not know, he does not know that he does not know, so his responses are generally uninhibited by self doubt. If he has a physcial "problem" with another he deals with it in a sort of natural let it happen way. He may innovate, or respond in some undrilled way because "it seems" the thing to do. Unfortunately this unconciousness (lack of self conciousness) is not a "force multiplier" and may merely allow him the illusion that he is doing well until he is hurt, or killed.
When training begins the instructor shows him how, and he begins to see that perhaps he does not have the natural talent he may have thought he had. He probably will become aware that he is painfully incompetent.
At this stage the student of the martial arts is now very inhibited and grossly worse off in terms of ability to defend himself or subdue an arrestee than before this realization.
At this stage the style may begin to make a difference, for the student NEEDS to achieve concious competence in some techniques before he or she loses interest/confidence and quits in disgust. There is a benefit to teaching at this stage some simple easily mastered techniques that the student can rapidly become conciously very competent in.
Most people in this society (the sit on your ass and watch the gifted giants play on the big screen TV society) do not know how to learn any physical skill. Nor have they ever truly experienced the wondrous feeling that accompanies the true mastery of a physical skill. If we can show them the joy in acquiring a physical skill they may stay at this long enough to begin to approach unconcious competence.
Unconcious competence occurs when your subconcious is driving the step by step train without your cognitive mind participating in that process directly. This is a feeling that many NEVER experience. This is the counter punch/kick technique that you literally watch yourself do in a state of mild surprise. "Wow, nice parry, side step, reverse punch" you think to yourself as the opponent is on his face in the classic fetal position making that sound. You know, the one that indicates that you got all his "air" and he is going to be 15 to 90 seconds in concious agony and doubt as he struggles for a breath.
Now I haven't forgotten that you asked for input about style. I chose Tae Kwon Do, but I do not now believe the style to be as important as the instructor. My instructor, Byung Yul Lee, actually taught his white belts as a 6th degree when I met him. His physical competence was obvious. I would choose to train with the most physcially competent person who could and would COMMUNICATE with me in some way what I am looking for.
It might be broken English, "no no elbow go under, you elbow out!" As he turns you to face the mirror and demonstrates the straight smooth motion that he wants. He might just rap your elbow with a knuckle, or smile in amusement, but the point is he has to be able to demonstrate correct form and to indentify when you improve. You and he are searching for the trigger, the physical sensation that will connect with your mind the sensation that your body needs to generate to make the technique work. When this occurs he has to have given you the right clues so that you recognize it and begin to reward yourself with posistive feedback.
So style is not as important as the instructor/student partnership in the process of exploration and discovery that makes a special bond, you may not even like the guy, but you are sure that he is going in the right direction with you in the long run.
Some style teach kick first, punch later, some teach sweeps and throwing techniques, chokes etc first, some last. If you train in most arts for 6 to 10 years you will be exposed to all or almost all of the techniques, in all or almost all of the styles.
If your goal is to be able to subdue to hand cuff and control suspects you may want to train in a style that seeks competence in these grasps, holds, pressure points first before we are training turning (spinning) techniques.
Which of these are those? I can not say, for though I began training in 1974 and trained formore than 7 years to the near exclusion of everything else in my life, my experience is limited.
I would hazard a guess that if you find a well rounded "adept" who is suited to teaching, you might be able to get him to teach you what you wish to learn first rather than later. In other words if you need to learn to "choke out" with a carotid artery occlusion techique, say so, and he should be able to teach you that earlier rather than later.
I would comment that as explained to me Hwa Rang Do is essentially Tae Kwon Do, true Hap Ki Do is Ai Ki Do Korean style.
Is there a best style, why of course the one I am teaching here, sign this contract please. NO, NOT IN MY OPINION; no one best style.
I apologize for the length of this post. I hope it not too esoteric for this forum. It is just that this is important and deserves a fairly arcane discussion. Hope this helps.
yours in marksmanship