A.T.
I used one for years before I had kids because hormone B/C made me fat and crazy depressed. It hurt when it was "installed" and I had some residual cramping for less than a week. It made my periods a little bit heavier and the cramps a little worse. It rarely got in the way during sex and if I was 100% "ready" it was not an issue - hubby had to do his due dilligence ;)
I felt SOOOO much better day to day without the hormone birth control!
However, IUD makes you more vulnerable to STD's so you need to be 100% sure that your mate will keep himself clean and monogamous before switching.