Copper IUD

I've been considering getting the copper IUD, but am afraid getting it put in will be supper painful. I don't have a good pain tolerance, and a friend of mine said that getting her Marina put in hurt a lot. So here are my questions:

1. Did you find insertion painful? Especially those of you who haven't had kids.

2. What are your personal pros and cons for using the copper IUD?

3. How effective is it compared to a hormon based IUD?

4. I am involved in a lot of physical sports and work, so would getting hit hard in the gut cause problems with the IUD? I would hate to go to the er because it stabbed me.