For me, the most striking aspect of his game (given the sort of player he was) was his, call it what you will, basics.
He was brilliant on the ball, had a great burst on him, could beat his man for fun, etc. But he didn't overdo that thing - in fact, he was actually rather subtle for a player who had his extreme qualities on the ball. He would frequently keep it rather simple. And he would move right - as in, he would play a simple enough pass and move into the right space after playing it.
He did the basics right, you could say. And then he had an absolute ton of spectacular ball playing ability on top of those basics (which is pretty much ideal, I would say).
He was, at his best, the very opposite of a show pony. He used his brilliance on the ball to deadly effect.
To answer the question, at his best he was extremely good and any suggestion that he was "overrated" is bollocks.