Van persie is a good player but i am saying he is not world class. World class strikers are drogba, aguero, higuain, benzema, rooney, villa, zlatan, tevez. These players do the simple things well, but also have extra magic with consistent ability to get past defenders and/or amazing pass vision.
I know adi will rip me up when he sees tevez on my world class striker list haha

RVP does the simple things well but where are the spectacular plays to make him world class? His goals are mostly tap-ins and all of his assists are from corners, free-kicks and hopeful crosses.
Getting 31 goals and 8 assists in a season does not make a player world class. I dug up some stats from previous years to show this point:
adebayor 29 goals and 5 assists for arsenal in one season.
michael owen 28 goals and 5 assists for liverpool
diego milito 32 goals and 6 assists for inter milan
forlan 33 goals and 11 assists for atletico
mario gomez 39 goals and 3 assists for bayern
luca toni 34 goals and 7 assists for bayern
dani guiza 27 goals and 6 assists for mallorca
Check the stats and you will see many similar players with big numbers. None of those guys are world class.