My experience has been that T's do think it is positive when clients are honest with them. Maybe they feel that it is good that the client has reached a point where they can be honest, especially if it is about the T. My current T has repeatedly said that she appreciates the "feedback" I give her about how what she says and does impacts me.

At the same time, her openness about listening to what I have to say that sounds like a criticism has helped me understand something else that she has emphasized more than once. That angry feelings, even directed at her, or any feelings really, are just like thoughts (especially of the sort that I don't often want to acknowledge) in that they are "just" feelings or "just" thoughts, they come in and go out of the mind. They are not to be given any real significance and it is when we act on those thoughts or in service of those feelings that we may run into some difficulty. I try not to "should" all over myself for having unappealing feelings and thoughts, and aim to acknowledge them but not give them too much weight. No one is a bad person because they have "bad" feelings or thoughts, and it's perfectly okay to share them with the T (assuming that it's helpful for you to do so).