The major downside will come when you meet a guy not impressed by fast hand. Jones Jr kept his chin in the sky, winged arm punches by the bushel, dropping his hands all the while. Too often he had too much weight on front foot. He is the most incredibly overrated "fighter" in history, woefully ill-equipped to fight a guy that came to fight and punched when roy punched. Relying on hand speed is fooling yourself. Learn to do it right, not like a cartoon character