I loved it! I had the time of my life.
You do have to have a great deal of responsibility. After all, you are in charge of a group of kids. I'm not sure what your camp does, but my camp did a lot of adventure exercises (Rock climbing, long distance hiking ect). With activities like those, they are fun, but you need to be prepared to take leadership in scary situations.
When I first started, I was afraid it wasn't going to be fun since I was going to be the councilor rather then the camper. But I got to experience everything the campers did, and got payed. I also stayed up later, had more privileges, and freedom. Also, the councilors always had something going on after the kids all went to bed.
We had little mini dance parties and games and what not going on in the councilors cabin (Which was right under the cabin for the campers. Campers were on second floor, councilors on first). It was a blast and I encourage you to do it. You will learn a lot and have a great experience.