Yes it is strong, but that's not a counter-argument. It could as well give an aura that kills everything.
4-6 pieces Raiment has only one gameplay and blends terribly with other potential sets. Only the 2pc bonus brings some potential diversity.
Oh look, it's getting worse :
2pc: Your Spirit Generators have 25% increased attack speed and 300% (up from 250) increased damage.
4pc: Dashing Strike spends 75 Spirit (up from 50), but refunds a charge when it does.
6pc: Your Spirit Generators increase the weapon damage of Dashing Strike to 12,500% (up from 8750 )for 6 seconds (up from 3).
2pc set is useless without full raiment, 4pc set is even more useless by itself, and 6pc has only one gameplay. GG