K.D.
I have the Mirena and I love it. I've had it almost a year. I got it because we're done having kids, but neither of us were quite ready to do anything permanent. Plus, I would get menstral migraines while on the pill and my periods were typically 5-7 days long. Since having the Mirena, I occasionally get headaches, but they aren't as bad nor as often. My periods are only 1-2 days and only require a panty liner. And that's when I actually get a period. I've skipped several and the time between them gets longer and longer each time. My doctor told me that within a year, most women stop getting periods all together and it's certainly something I don't miss.
My sister-in-law had the Paraguard copper IUD and her only complaint was very heavy and long periods (typical of that IUD) and she had it removed and was pregnant in 3 months.
The nice thing about an IUD is you never have to worry about it. The Mirena does have a small amount of hormone, but it typically stay localized in the uterus and they say it's safe for breastfeeding mothers. And it can be removed any time if you want to have another baby and fertility returns to normal almost immediately.
With anything medical, there are risks involved, so be sure to read up on them before getting any IUD. I went into it knowing that there were some risks, albeit small and I hope for the best. My only regret was not getting it right after my babies were born. If I'd known how easy it was to insert (even a regular exam was more uncomfortable for me) and how much easier it would make my life, I would've done it sooner.