He's best for me when he's on the team-sheet as an out and out striker, but still does his dropping back, number 10 thing a bit. In comparison to the world's top number 10s, he's not that special. It's the fact that he is able to be such an influential playmaker whilst doing his job as a striker that makes him exceptional.
That's why he and RVP are so dangerous together, I think. One second they're an old-fashioned front two, both proper strikers. The next, they're Barcelona-esque false forwards, playing it out of the midfield with little one-twos and leaving the CBs no-one to mark. Both very versatile and very elusive.