I absolutely loved this program!! If you have the opportunity to go travel to South Africa with GYSA, you should definitely should.
During my time with GYSA, I helped out with the Community Development Program. The program was very flexible--I spent my first few days in Cape Town visiting different organizations to put together a personal volunteering schedule that I was excited about. Ultimately I spent most of my time working in pre-schools and and a disabled school in the township Masiphumelele. The time I spent volunteering was both meaningful and enjoyable.
GYSA is a wonderful and unique program for a number of reasons. You are living in a lovely house surrounded by other people your age, in one of the most beautiful cities in the world. The house atmosphere really accelerates the friendships you make. When you are living with ~10 other people, you quickly become friends.
When you're not volunteering (or surfing or helping with Hillsong) there are almost unlimited fun activities to participate in. GYSA helped my group organize a number of touristy activities, such as visiting Robben Island and snorkeling with seals. And even just planning among ourselves we managed to put together a variety of fun weekend adventures. Also, the night life in Cape Town is great. There was never a boring moment.