I’ve used both methods, and think they’re both fine. The NuvaRing was good because it was a lower-dose form of hormones, a lot like the Pill, but better (in my opinion). It was a good option. The only issue for me was the hormones. That and I forgot to insert it on time once or twice over a few years’ time.
About four years ago, I decided to go with the copper IUD (Paraguard) because I decided to avoid taking hormones, and the IUD was the most effective BC method available. (Needless to say, I’m also in a committed relationship, so I don’t need STI protection. I should also mention that I was about 32 when I had the IUD inserted, and had no children (then or now). Often it’s not recommended for women who have not had children because there’s an increased risk of the IUD being expelled from the body.
My IUD experience has been excellent. My periods were extremely light on hormonal methods, and naturally increased with the IUD. For the first few months my periods were very heavy, but that’s normal. Now they’re heavier and longer than when I was on hormonal BC, but it’s not a big deal. On the plus side, I love not having to think about birth control at all. Also, the cost was low, in a long-term sense (my IUD can be kept in place for 10–12 years), though it was a lot to shell out all at once (about $300, I think). The strings were a bit long for my partner at first, but I had them shortened and they aren’t a problem anymore. Even when they were longer, I think it was more distracting for him than actually painful.
What else? When it was inserted, it was pretty painful, but not for too long. Maybe a few minutes? I felt a little tender and tired for the rest of the day, but that was it. All in all, I think it’s a good option. Personally, I love it.
If you don’t mind hormones and like the idea of not having a period (or much of one), the Mirena IUD is probably a good option for long-term, reliable birth control. From what I remember, the hormones in the Mirena IUD are still far lower-dose than even the lowest-dose pills. And the NuvaRing is also lower than most (or all) pills.