For about 5 years (during college) I was a ropes course facilitator. I worked with groups of kids as young as middle school all the way to corporate groups of adults from big companies. Every group came to the ropes course seeking the same thing: development of inter- and intra-personal problem solving skills and teamwork strategies. A major part of this experience is debriefing each challenge and deterimining what worked, what didn't work, and "what did we learn."
Most groups left at the end of a day or a weekend feeling successful in achieving at least part of the "teamwork/problem solving" goal. But more than that, almost every individual ended up admittedly leaving with a better sense of self.
I believe self awareness is vital to success in relationships, which is the building block for success in everything else in life. I think self-awareness is learned best through challenge - being forced to step outside your comfort zone. I believe developing self-awareness is a life-long pursuit, and those who are actively in pursuit of it are always bettering themselves. I think it healthy for individuals - but again, the active pursuit of it ends up enhancing all group situations as well.
I do not believe that "self-awareness" is the same thing as having high "self esteem." Rather, I think it is working to gain an understanding of your personal strengths and weaknesses, how to communicate your needs with others, and how to use what you are good at to help others.