Taiji sword work is completely different from iaido sword work. First, the sword is much lighter, which affects the movement of the blade through space. Second, the double-edged blade means I don't have to be as aware about which way the blade is facing. Third, the movements are slower and more deliberate, even though they aren't necessarily less powerful or dynamic.
This morning, I started working on "body geometry" (my term for it) with Master Shirley. The primary focuses of these early lessons were economy of movement, relaxed form, the sword as an extension of the arm, and moving along a plane. It has been great to remove rigidity from my stances, to apply circular motions toward the angles of the sword and my body, and to learn (again) how to channel energy as it spirals up from the ground while my body moves but my arms mostly don't (at least in relation to my body).