One should know when to use short non-powerful attacks, and one should know when to use slow but powerful attacks. If use either one in a thoughtless manner then all you will do is tire yourself and waste a lot of energy and strentgh on a bunch of careless attacks. IMO I believe that you should try and make your attacks as fast and consistent as possible at first and as your opponent becomes weary and less responsive, then you should use stronger, more powerful attacks. I think everyone agrees that whenever you use an attack that offers more power that you sacrifice a lot of your defense at the same time as the attack, so it would only make sense to wear your opponent down before doing so because then they will have less reaction to respond to your open spot in your attack. That's what has always worked for me. But you should do whatever works best for you. That is JKD isn't it, taking what works for you and using it instead of what flaws you?

Do what is appropriate for your situation. Take into consideration the assailant's intent and perceived capability, other potential assailants, the physical environment you're in, and what you wish to accomplish with the encounter.

Does anyone have a link to a video clip of someone actually doing a straight blast?

Don't know of one, but if you google "chain punching" you'll see pretty much the same thing. If anything, this is a great move if you can get directly to someone's head - continuous, quick punching should theoretically rattle their brain around so much to KO or seriously debilitate their motor skills. It's a nasty trick, but it needs to be set up properly.

A lot of JKD folks such as Paul Vunak seem to swear by the straight blast. I've seen it used before in a street fight in Hawaii, where MMA is extremely popular. It was a smaller guy (though in excellent shape, and clearly a martial artist by his response), and he did a straight blast to a much bigger guy. Like most real fights, it went to the ground, but the smaller guy clearly knew BJJ as well and he seemed to take it to the ground on purpose... the bigger guy was on top, but the smaller guy immediately had him in full guard with the legs and then he was able to leverage him, turn him around on his back and straighten his body. It looked like he was going to do some sort of submission, but the fight was stopped by other people.

But the blast really stunned the guy and he nearly fell over before it was taken to the ground. He walked away with a bloody face, and the smaller guy had no visible damage. He didn't do a complete centerline blast, but got some face strikes in too.

Good stuff. The smaller guy was totally dominant and the blast was completely effective against a much larger opponent. It allowed him to do what it's intended for: throw him off balance, stun and take control.

the straight blast is like a right cross in boxing right???
yeah but it's hard to tell how much force it has when you're puching the air...but if it hits something then you know how good it is...(i've used it alot it's better than what my teachers told me to use )
it's even better when you aim for the nose,mouth,eye

Alot of people swear by the straight blast because it was rumored to be one of Bruce Lee's favorite techniques.

As suggested above, I still ponder that if you used more powerful punches within its charge, instead of series chain punches why not 1-2 fast hits & then a power shot. I wonder if all that tussling and the other strikes would be needed? Now its always wise to have a alternative plan, which is all I'm saying.