I really hate questions like this because everyone's experience is based on how their body responds to foreign objects and/or hormone therapy of any sort.
So what one person experiences is not necessarily going to be what you will experience. The reason I am telling you all of this is because my body (as with most of the women in my family) is incapable of absorbing added hormones properly. I have had sever endometriosis almost from the time I began having cycles when I was 11. The pill and all other formes of hormones to help "regulate" me have done nothing but make matters worse. Mirena has a hormone in it.
I was sent to a specialist for a hysterectomy and she talked me into trying the Mirena as a "last ditch" effort. At first it seemed to work.
By the end of the first year I was so sick all the time that my PCP had me tested for mono. The thing is my symptom were not typical of problems with an IUD, and were so gradual in coming on we never suspected that's what it could be.
I was so exhausted I could barely get out of bed to care for my 3 kids. I got sick if you looked at me cross-eyed or said "boo" And my pain from my cycles came back with a vengence.
The pain caused me to have the IUD removed, as I had not related the other stuff to my IUD as yet...I figured if I was going to still be in pain with it too, I didn't need to have it in. It took the doctor 4 attempts to pull the IUD out as it had managed to attach itself to my Uterus. That last pull was very painful. However, 2 to 4 days after the removal of the IUD all the other symptoms went away...
So...as this is atypical of what could happen, all it can do really, is make you more worried about any decision to get one. If your body is typically fine with the pill or the patch hormones, the only thing left is will it accept a foreigh body in your uterus? Mine did not.
I hope that you get responses from women out there who claim to have had a great experience. The problem is, that doesn't mean your body will respond as mine or as theirs...Ultimately, your body is your own and you have to make the decision based on how you have responded to other treatments in the past.
If you are the type who tends to get some or all of the "symptoms" to watch out for, then I would suggest not doing it. If you are the type who typically has no issues with other things you have done for your health, then go for it. You just won't know for sure untilyou try.
I wish this was one of those things that had a simple answer, but it isn't.
Good Luck... ;-)