We have the harness pictured below. It is nothing fancy by any means, but in our opinion, it gets the job done. We started using it when Egan was pretty small, and it worked great. Now, he's a lot bigger and it is still easy to carry him for long periods of time. So far, Egan has only faced inward, but soon we will be able to let him face the other direction. We will even be able to turn him around and put him on our back once he gets bigger. I think the main downside of this style harness is that it takes some work to adjust for 2 people of different sizes to use it. That is a big reason that we got our other sling.
We got a second carrying method recently that will be easier for me to quickly put on and take off when out running errands, and it will also allow us to size the harness for Blake so he can use it more easily. I actually got this one off Ebay, but it is a sample from a name brand company. That means we got an expensive sling for $20 including shipping! I'll take that any day. It is just a simple loop of fabric, but I really like how it sits on my shoulder and supports my back. Egan likes how snugly it is. We didn't have this sling when he was itty bitty, but they say you can use them for brand newborns. I do like how he sits in it now. I can either do him in front like in the picture I took at the grocery store below, on my hip, or lots of other ways. It is so flexible, easy, and fast!
Here's another use I've found for it... Nap time while out to eat! Here he is in the restaurant booth. This sling is also reversible and has a matching brown, orange and cream fabric on the back. Don't you just love how it is "our colors"?