Lovesbaby, I will choose natural if you are ok with it too. Reasons:
1. It's non invasive
2. I dont like "surgery" unless it's absolutely necessary.
3. Uterus lining will not be scrapped thinner (that's what my sinseh shares).
But the cons of natural is the waiting part. You wont know exactly when the sac will be passed out. And you have to be prepared to see the passed-out remains. I think I read someone from another forum that she took the remain back to the clinic (not sure for what reason). Or you can simply flush it away into the toilet.
I experienced both. Honestly, both are just as painful (heart). Just choose what you think you are more comfortable with. I flushed away the remains in my 2nd mc as it was an empty sac. There was never a heart being developed.