It takes some getting use to. I use to teach rappelling and I had problems using a climber at first. I didn't want to get over fifteen feet off of the ground because I didn't trust the equipment. I have been using climbers for over twenty years and it is second nature now. I can go up to thirty feet without thinking about it. The good news for you is that the equipment is a lot better than it was in the late 80's.

Learn your equipment, don't rush it, and you will gain the confidence to climb and sit all day.

Good luck!