I had the mirena I'D and loved it. Cramping was awful the first few days but they say it was because I had never been pregnant. Outside of the initial cramping I had no cons from the IUD. No period for two years but did feel in my breasts when I ovulated. I recommend it to anyone who is thinking of getting one.
I've had both in my life and have been happier with mirena, but it's definitely a personal choice depending on your lifestyle and priorities.
Micro-Pill
Pros: no procedure to start/stop if you change your mind about timing, painless, helps keep your skin clear.
Cons: depending on your healthcare plan may cost $ each month, you have to take it every day, and you have to take it at the same time every day. I personally had some breakthrough bleeding on the pill - less on the micro-pill but still some.
Mirena
Pro: you can't forget to take it and there's no time of day concern. It lasts 5 years so you literally don't have to think about birth control for 5 years which is amazing. My healthcare covered it 100% so I saved myself about $900 in pills. Plus no more breakthrough bleeding, yay!
Cons: it hurts a little bit when they insert it, my monthly cramps were worse than they were on the pill, and I noticed my skin breaking out more. Some people have reported hormonal changes after removal. I didn't notice anything.
Re: Trying up decide if I should do morena IUD or mini pill