exhaust power gains

Hey fellas, i own an09 250 ninja and would like to know:
1.How much of a power gain would you get from a slip on exhaust?
2.How much of a gain from a full exhaust?
3.is a micron pipe better than yoshimura?
4.and final question is, what else can i do to get decent power gains?
1.How much of a power gain would you get from a slip on exhaust?
2.How much of a gain from a full exhaust?
3.is a micron pipe better than yoshimura?
4.and final question is, what else can i do to get decent power gains?