Quite positive. Often they are angry at some personal abuse done to them by a church, and that is understandable, and I would feel the same in their position.
Some atheists are absolute jerks, but I don't think it's bc of their atheism:-P.
If anything, they may be more self-aware - not always - bc they are forced (to a greater degree) to wrestle with matters such as who am I and what am I doing here, that religious people should also very much do but some are lazy and do not:-).