Birth Control questions/issues?

Hello there.
I was recently reading up on different birth controls because I am thinking of getting something. I am really only going between two options right now, which are the mirena and the non-hormone IUD. Both of them have a few pros and cons.
The mirena IUD lasts for something like 3-5 years, and releases a hormone directly into your uterus. The problem with this, is that the last time I took a BC, things... Didn't go so well. My body reacted horribly to a very low dose of pills and I've been nervous about them ever since then.
The non-hormonal IUD can last up to 12 years, but obviously... Theres no hormones and it is made of plastic and copper. This one also seems to be cheaper to buy than the mirena.
I guess my question is, if anyone else has one of these, how does it work for you? Is it really effective?

I have the copper one. It's the best birth control I ever had. No hormones to mess with my mind, no prescriptions to refill or pills to remember to take-- and it lasts just about forever!

The only downside is that I now have a regular period and it's much heavier. I haven't had any problems with cramping. I think I might have had cramps the the first couple of months, but it's been 8 years since I had this put in, so my memory is foggy.

I have used the copper one as well with no real problems. I have heard the mirena is more effective but it can mess with your hormones.