I have one for sale on the trading post under (African) Baby Wrap, so if you are interested after wading through the reviews you read please pm me!
I bought it after wanting something that was a little more hands-free than the sling, and I got what I wanted, but was still a little frustrated.
The +s were that it is very secure, and tied baby close to my body so that I could do bending-over things like laundry, gardening, etc. The back carry did not work particularly well for us because my baby didn't like being so far away, but he was little when we were using it, so it might work well with an older child. I think the issues we had with it re: the back carry were similar to those you might have with another back carrier for infants.
I also like the way that it centered his weight on my body and how it kept him relatively high on my chest/belly, making it easier to walk/hike long distances because my stride was more even and less encumbered.
One - is that it is a little more complicated than it looks, with a chest strap that provides some stability, and a pouch that the baby sits in on the inside. It probably only takes 2 minutes to put on, but after the ease of the sling it seemed complex.
Stacia -- intrepid mama, midwife, and doula. Changing the world one 'zine at a time.