One superpower or many powers?

In class we have discussed three different scenarios of a world power: 


1) Hegemonic - One big power 
2) 2 superpowers - two countries share the superpower
3) Multi-power - More than one country has the power 


Many argue about which power benefits more. Personally, the multi-power system benefits the system we have now. Countries trade amongst each other more freely now than ever and need the cooperation and the ability to check and balance each other out.