For convenience, nothing beats a ring sling, it is a fast, user friendly carrier. I think that I discovered all other carrier types before I tried a ring sling, and I wish I had used one earlier. The one I tried was a beautiful teal Comfy Joey linen sling. Previously, I had thought that SSCs were the most convenient but I definitely found the ring sling was better. You just place the ring sling over one shoulder, pop your baby in and you are good to go.
I used this carrier with my 7 month old. I mainly used at home for shorter periods of time since it is a one shoulder carrier. I would put him in it when I was getting dressed in the morning and have him in it until it was time to go. I also used it a couple times when I was taking my children somewhere I would be staying a while. I wore it in to a birthday party so I could carry my baby, a present and have a hand open for my other child. I continued to wear it at the party until everyone was acclimated and then took him out to crawl around with the other kids.
Another thing, I like about about this Comfy Joey ring sling is that it is pretty enough to wear for formal or dress up occasions. I think ring slings are the best for this. Other carriers can really detract from what you are wearing but a nice ring sling can really enhance an outfit. I took it church and ended up using it. I was glad I had it because the tail makes a handy nursing cover.