Experience with the IUD?

I recently switched from the depo shot to Yaz birth control but my stepmom doesn't think this method is good for me since I'm pretty forgetful and she thinks it will make me very moody. The only other method I could think would work for me is the IUD and she seemed to think it was a pretty good idea. So anyone who has tried or heard of it, do you think the IUD is a good thing or bad? Do you know how if affects the menstrual cycle and weight gain?