I think if a T needs to prepare, then they should prepare.

I know a lot of teachers who do endless (to me) preparation for their classes. Yet I find them to be very poor teachers. Others appear to never prepare--everything seems spontaneous and genuine--and they are brilliant teachers. I suspect both prepare, but some prepare in the ways that enhance their work, and others just spin their wheels.

So some Ts, maybe despite lots of time spent recording and reviewing notes, consistently miss the boat. Others, blessed with fabulous memories and who maintain a strong engagement with their clients, may spend very little time preparing, yet regularly achieve a profound connection with clients.

But I think the responsibility for learning ultimately lies with the student, regardless; and the usefulness of a session ultimately depends upon the client. Teachers and Ts can just make the task more or less difficult/ tolerable.