reaction
Frogman ,
I guess your quick reaction doesn't have much to do with your Martial Art training!!! I've learned that human has ,so called "protection-reactions". For example when you move something to your eyes quickly ,your eye will close by sure. The difference to normal reactions is the neurotic control: In the regular case, the stimulus which you receive will go through your vertebral column to your brain first and then back to the reactor (muscle). When you do a protection-reaction ,the stimulus will go to the vertebral column and then straight back to the muscle. So you don't need your brain for this reaction.
I am not sure about that you are able to make this reaction faster. I think ,what you learn in Martial Arts is to CONTROL these reactions. I mean when you punch a NON- M - artist right into his face he will also try to protect his head with his arms. But a M-artist will do what he did a hundred times in training. And in this case it won't be such a "protection-reaction" ,because he controls his movement!!!
Don't be afraid of walking slowly.
But NEVER halt.