Not sure how old you are, etc. but.... My doc recommended paraguard (she does both) since I didn't like the hormone aspect. The pill aggravated my stomach, I didn't want to deal with hormones, increased risks associated with hormones, etc. The cool thing about paraguard is it lasts for 10 yrs so it will see me into menopause unlike the Mirena that only lasts 5 yrs (I think). My friend on Mirena has worse cramps than I do, but that may just be here. Also, I know that a lot of women will eventually lose their period on Mirena so that might be a plus for you.
Having it put in was nothing that a few motrin couldn't take care of. It was uncomfortable for a few minutes, but nothing compared to labor. My periods have been fairly regular but a bit longer (I had it done in Oct/Nov) and cramping has not been any worse.
I decided on the IUD after researchign and talking to my Dr. At first I wanted my tubes tied because I was put off by the idea of having something in me. I've since talked to a couple of women who've had way worse symptoms after having their tubes tied. Plus, surgery is nothing to take lightly. IUDs can always be removed too if it bothers you too much or you change your mind about the kid thing.