Remind me again, what did I say his top level would be?
I think he'd do well in Germany or Spain, a bit below the top. I'm still not convinced he's quick on the ball enough to play on the absolute highest level.
On the other hand, he might adept to that too, because he's definitely better than what I though he'd be a few years ago amd he's still very young. He's added goals to his game now as well and is maturing in his behaviour on the pitch, though he still gets a few really silly yellow cards for losing his head sometimes.
Bottomline it's impressive that he is our captain in a rather successful Feyenoord team at this age.