The benefits of babywearing include a decrease in crying, and an increase in attachment, emotional learning, and most probably peaceful societies. I loved that I could soothe my baby while getting the dishes done, dinner made, eating lunch with friends, walking on the beach, etc. I couldn't imagine leaving Isla in her carseat "carrier" and hardly touching her all day long like so many moms do all over our country. Babies need to be held and touched, and slings and other babywearing devices make that possible while enabling mamas to use both of their hands to do other things.
We didn't know what baby carrier we would need, and in the end we (basically) tried them all. The two that looked to be the easiest were the sling and the BabyBjorn, but I found that not to be the case. Although she loved her sling in the beginning, it was difficult to position her in a way that didn't make her look like she was about to snap in half or fall out. Also she tipped the scales at 9 lbs. at birth, so she quickly outgrew her sling. We often stuffed her into an organic newborn insert and then into the Ergo, and that worked out fine, but my favorite carrier for the earlier months was the Moby wrap. It worked because I could carry her facing in, facing out, or sling-style, and she strongly preferred one style over the other two at any given point in her development. It was really soft, and breathable, and easy to throw it on quickly. Also, my husband could use it without any adjustments. As she has gotten older, I've stopped using the Moby at all, and just use the Ergo. We both love it, and Isla likes riding in it on the front as well as on my back.
Had I known then what I know now I would have bought both the Moby and the Ergo, and skipped the sling and the Bjorn.