I did a ton of research on Mirena vs. Paraguard when I was looking into IUD.
I eventually wound up having Essure done, becuase we're DONE with having kids.
That said, at the time, I chose Paraguard because most of what I was reading (granted, you find a lot of negative on the net), was about weird side effects kicking a couple of years after having it. Most commonly, weight gain (like, after 2 yrs), and emotional roller coasters from people that could only attribute it to the Mirena. meaning, things went back to normal after having it removed.
So....just do a lot of homework before you make a decision. How do you typically react to hormonal BC?