I LOVE mine. I'm on my second - I also had one between the girls. I have been on nearly every type of hormonal BC imaginable and Mirena is the *only* one I have not had side effects with. No emotional issues, no weight gain (I'm below pre-Lil weight currently), no hit to my sex drive, no acne, etc.
I decided on Mirena vs. Paragard because Paragard tends to make periods heavier, whereas Mirena does the opposite. Sans BC my periods are pretty debilitating - vomiting, migraines, cramping that renders me useless for 3 days, etc. Mirena makes all of that go away. I love it so much that I've said, even if my H got a V, I'd still use Mirena. Best BC ever. Hands down.