I used a Baby Bjorn in the early days with my DS, but he got so heavy that it killed my shoulders (I even tried the Active version and it made NO difference). Once he got to 4 months old I bought an Ergo, that way I didn't need to buy the infant insert. I LOVE the Ergo and would recommend it to everyone!

I have a pre-loved baby goods business so I am fortunate to be able to test drive lots of different carriers, so cost wasn't an issue for me when using the Baby Bjorn for the first 4 months. If you do buy the Air carrier you could always sell it again on eBay and get your money back.

If I had another bub, I would still use the Baby Bjorn in the beginning because I reckon the infant insert on the Ergo looks fiddly and I've heard of some people who hated using it.

Anyway, that's my rambling opinion and I'm sure it didn't help you one bit LOL!