I have had an IUD (Mirena) for 16 months now. Before it, I was on the pill and my hormones were out of whack. My FNP discussed Mirena with me and we decided it was a good option. I have had nothing but good experience with it. I don't even get a period and have no crazy hormonal swings. The low dosage of hormones it releases are localized to the uterus. I'm even tempered all month! It hasn't hurt my sex drive, or caused any problems at all. The only way I know it's there is the "strings" that are attached to it. It's our 5 year BC plan and I love it!
I think everyone is different and it obviously isn't for everyone, but I give it a thumbs up!