To speak very generally, exploring typology has helped me notice my habitual way of living in the world, and little by little I'm able to pay attention to more and more. It's thrilling to catch yourself in the act, and humbling. So my world expands and I'm able to be more compassionate to others as well, since it is obvious that there are several other legitimate ways of surviving. The process of looking is equally important to being able to find your type, and even mistyping provides valuable lessons. Highs are higher, lows are lower, and through it all I'm able to remain more objective.
I have felt that in some romantic and therapeutic relationships I was looked at as an Enneagram type, and that felt dehumanizing (says the 4). A therapist once told me that she thought of me as a 4, and I felt that my concerns were dismissed because 4's shouldn't be encouraged to dwell in negative experiences of the past. This therapist wasn't particularly interested in the Enneagram though, and I've had a lot of productive sessions with teachers who work primarily with that system.
Personally, the most potent game-changers have been instigated by the natural changes that come with age, and radical shifts in body alignment. If I can bring myself to do it, vigorous (as in, I-can't-tell-the-difference-between-sweat-and-tears-and-I'm-about-to-scream-I-don-t-know-who-I-am-anymore vigorous) exercise even once a week is worth at least 10 visits to most therapists I've seen. Massage, rolfing, NCR, Feldenkrais, Alexander technique, and meditation have all been especially helpful for my particular flavor of personality.
P.S. Obsessing over typology has also proved to be a potent form of procrastination.