Hi,
Definitely the mayawrap sling for me. I had a Baby Bjorn, but after a few months it started to give me back and shoulder problems if I had been carrying the baby for any length of time.
I have carried my daughter in the Mayawrap since she was three months, she is now nineteen months and I still carry her in it (and I'm pregnant) and there are no problems. My daugher has breastfed and slept in the Mayawrap, and all in complete comfort both in the fabric and next to Mummy.
Jools