My CBT T I have been seeing since 2011, and I have a comfortable relationship with him. He self-discloses on a very limited basis when it's useful for me, so I only know the basics about him plus a few random things. From recently talking with him about self-disclosure, he is pretty much the same with all his clients.
My other T I have been seeing for a little over a year, and he self-discloses a lot. I have found it helpful in that we have things in common (interests, sense of humor, some past experiences) so I kinda feel "more normal." I don't ask him many questions on my own without being prompted by a story or sharing on his part. Once in a while he will say something or tell a story and I am left pondering it's relevance.

We do joke and just chat sometimes too, so I think that maybe he has just thought of something to tell me that I will like. He thinks it's therapeutic if I laugh. Regardless, he hasn't ever said anything that has been harmful to me in any way.