Its mostly pointless after 5 when you get the 5 extra create a class slots. At least in MW3 you could spend the tokens on double xp or double weapon xp and tailer the experience to suit you. I dont know why they wen back a step with blops2? I suppose only prestiege masters get to unlock everything, thats another incentive.
Truth is though prestieging isnt very interesting anymore because hardly anything new has been added to it. Ive gone full prestiege in blops, mw3 and now soon to be blops 2 but its a very tired system that needs some thought and love put into it.