Wearing 4 set pieces will basically give you a free sweeping wind, since the 3 set bonus is more than enough to offset the cost (5 spirit).Inna's Grandeur 2 pieces: [+130 Dexterity]
Inna's Grandeur 3 pieces: [Increases Spirit regeneration by 0.3333333 per second]
Inna's Grandeur 4 pieces: [Gain 10 Life per Spirit spent] [ Reduces resource cost of Sweeping Wind by 70 Spirit.]
That will be pretty amazing for some builds that requires other spirit spenders + sweeping wind.
Keeping my fingers crossed for the new buffs, but I'm thinking the daibo might also be a viable choice after 1.04, seeing what they did to the 2 handed legends [2 handed gets insane critical damage %]