The answer to that could be an entire post all by itself. In short, only positive ones in my experience. It's meditation x100! My creativity has steadily been increasing, with the occasional spike. Is this because of DMT? I have a fair bit of experience now and I can confidently say that there is no difference between the creative state and the meditative one. The world/mind quietens, you get absorbed in the impressions your mind shows you and all things seem to do themselves.
My brain work more visually now, I see things more clearly. Both my immediate surroundings as well as the simulations I run in my mind. My mood is better too.