My take on it.
I remember when I liked DBZ, I was in elementry then, but that's beside the point. Many people who got into anime started by first liking DBZ (Not all, but quite a few), so don't let those goons who yell 'I HATEX0R DBZ U SUX' get to ya. In addition, they knew they were in for a DBZ flash, I don't understand why they go out of their way to watch what they don't even like? They most likely have too much time on their hands and want a soapbox to stand on.
Normally I watch DBZ NG flashes for a laugh, they normally suck so hard that it's funny (However I don't go out of my way to leave rude reveiws like many of the jokers on here.) I was surprised here.
I will agree that the flash gets a bit boring at times because it does the same predictable things that they do in the show (But your goal was to be accurate to the show, so you succeeded in that. Kudos!) Your animation skills are fairly decent (Read as: Pretty damn good), however, the parts where you tripped up on facial anatomy were noticable, but they weren't bad enough to really detract too much from the overall product. I also agree that there could have been a bit more animation. (Though animators have definately more pateince than a normal artist like myself, I've tried to animate, it's hard, I understand you cutting corner)
Keep at it though.