I love the length, but I must admit, I am a little concerned about his lack of quickness and burst.
He's deceptive. Because he has such great balance, precision and efficiency of motion, he doesn't ever look like he's in a hurry. He can look 'slow'. But folks said the same things about Pierce and for the same mistaken reason.
A good video to watch is the "pull up game" vid on Fultz on DraftExpress:
http://www.draftexpress.com/article/Markelle-Fultz---Pull-Up-Game-5742/That video is a bit dated now (it was posted last December) but it demonstrates some important things about why Fultz is so highly rated and perfect for scoring in the NBA. For one thing, it obviously shows just how polished his skill is at creating a wide variety of shots off the dribble, many with almost deceptive ease. But it also shows that he does indeed have 'explosive' ability when he needs it. His step-back is so sudden that it is sick how helpless it makes the defender look. But more to what you are talking about, scroll towards the end of the video. That's where it shows how all those hypnotic pull-up moves sets the defense up for him to explode to the hoop.
The kid got to the line 6.7 times per game. He has a great first step and can drive.
Watching him at work reminds me so much of Pierce at times it's eerie. How many times did we see The Truth casually work the ball from the top of the key over to the elbow, give ever so slight a lean as if he was thinking about putting his shoulder down to drive ... and then suddenly explode back and up for the jumper? I still have a vivid memory of him doing that to Artest in the Finals.