If you do mean the bubba moe, I have one. It was really useful from 2-6 months. Earlier I found getting bub in to it difficult (I think I would have had that problem with any carrier), and after 6 months there was too much weight on one shoulder.
It's not a completely hands free sling - you will be using one hand to steady most of the time. The best thing about it is that it scrumples up and fits easily into a bag.