I do love my mirena
I had it inserted under a GA as my Obs told me that it does hurt a fair bit if you have not had a natural birth.
I did bleed/spot for about the first 3 months or so, and have not had a period since (4 yrs now)
I started other meds at the same time, which have some pretty awful side effects, so I am pretty sure I havent noticed anything from the mirena
though I do have to say, my libido is certainly reduced (though I wasnt exactly super-active beforehand anyway)
anyway - my choice is a mirena or a hysterectomy, so I will be getting another one when I have to have this removed in a year