Poor kid doesn't even look like he feels safe in the one on the left. Lol. When I baby wore I used a babyhawk. I loved it but the baby didn't after about a month.
I have a Maya wrap and I love it. I've tried others, but the Maya is so versatile and comfortable.
its called the Playtex hammock--it is similar to a sling except that it transfers the weight across the shoulders like a messenger bag so there is less strain on your neck.
Sling or I just carried her around a lot too.