We have a lot of carriers. A hotsling, native sling, moby wrap, peanut sling, and ergo carrier (to my credit they were bought second hand or gifts, so it isn't like I got them all new). Norah is not a fan of the sling, she gets way too smooshed in there and I am convinced she can't breathe. She is a bit too young for the ergo (she has to be able to fully hold her head up on her own). We got a Baby Bjorn for free from someone in the mother's club I belong to, and we have finally hit the jackpot. She fits, she loves it, and I am satisfied she isn't being suffocated.
We went on a field trip with her strapped to BVZ and she promptly passed out.