I believe in the "Best I've Faced" article on Mike McCallum, he listed Julian Jackson not only as the "Hardest Puncher" he faced, but, also as the fighter with the "Fastest Hands."
Good fundamentals and form. Was seldom off balance. More composed than for example Benn. But he relied so much on his power that he became a bit one-dimension despite his good fundamentals. He hardly put his punches together or moved his head for example. He didn't vary lighter punches with heavier, but threw every punch with bad intentions. He had a decent jab but didn't really take the time to establish it from what I've seen of him. This made him predictable, but only the best could fully take advantage of it.