If you play Tau there's no reason not ally with Farsight, its pretty easy to reap the benefits of scoring crisis suits for a point a piece.
I'm on the fence about the fusion blades, they seem a little unreliable with the shutting down on a 1. What I really like is the amulet the fact that you can deny the witch on 4D6 is pretty big, but it also means you have to either forfeit the Tau signature systems or take a secondary suit HQ.