I signed up for 6 weeks..
I ended up doing one week of intro, one week of teaching, one week of construction and one week of turtle conservation..i decided to take off the remaining two weeks to explore and do some trekking.
Overall it was an awesome experience.. It was a great program to get out of my comfort zone, talk and meet new people.
As for the programs, it was definitely a lot of money for what you got to experience. For example, the construction program was an additional $50 per week, which they say covered the supplies and concrete, but there were about 15 people working on the same project during one week. Thats a lot of money for a bunch of bricks and concrete. Plus the project wasn't that organized as many of us were just standing around for half the time.
The teaching project was not that organized as well. We weren't given ciriculim and were responsible for teaching whatever we felt like each day. Sometimes the students had already learned it.
Overall the teaching was challenging but I think it was a good experience in that it taught me to think on the go, and improvise.
The turtle project was probably the most fun. We got to feed the turtles twice a day, clean their tanks, pick crabs/seaweed and on the Friday, we got to release a turtle. It wasn't that much work since there were so many people doing the same project at once, but the turtle project was the most memorable. Also the food was a bit better than in ubud. There was also a cafe on the beach that you could go to if you got hungry during the day.
Overall I wouldn't say I made a huge difference, as I only did each program for a week. It would have been nice to have stuck to one program, but on the other hand I'm glad I did a variety of tasks while in Bali.