The Fast and The Furious
At some point, the practitioner should appropriate a method of training dedicated to developing speed; speed should take precedence over power. Atemi (strikes delivered to vital or specialized targets) were created to down formidable adversaries quickly, so the aspect of power here becomes moot. Being "The Fastest Draw in The West" had nothing to do with the size of the revolver, and provides a good analogy for this particular aspect of the martial arts. Blinding fast techniques can get past your opponents reflexes. A "hit and run" artist is one who can score points with strikes, and quickly move out of fighting range (ma-ai) before being countered. So speed can enhance both offensive and defensive strategies.
Speed is relative. What if you're matched up with someone who is faster? A common lament of trainees is that they can't seem to dodge strikes in time. A good way to circumvent your opponent's quickness is to watch for clues. In boxing, they say your adversary "telegraphs" an intention to hit. Looking for the ol' wind up will give you time to either get out of the way or block and counter. A drop in stance or some other sudden movement, no matter how subtle, can be signs.
Trying too hard to be fast all the time will interfere with your poise, rhythm, and timing; this can cause you to tire and slow down. Never sacrifice proper form for the sake of speed. Speed should come as the natural result of dedicated training over a period of time.