I've only played the Kinetic Combat (Tank) spec for my shadow, but this is what it looks like to me. The infiltration tree in shadow is more of a rogue melee style, the telekinetic sage is more mage-ish. Both have a balance tree, which is a combination of both melee and ranged. I would imagine that the shadow balance leans toward more melee, whereas the sage is probably more ranged. If you like the telekinetic gameplay, then run with it. A friend of mine is using that tree now and he loves the DPS that he's getting out of it.