I like the idea of a Moby, but I didn't like tying it. I had read that you could tie it on at home and then pop baby in when you got to the store or wherever, but I found that sitting down would mess up the whole setup and I'd have to retie it anyway. And where we lived when I discovered this wrap was really rainy and wet, so the bottoms were always getting gross.
I discovered the Baby Ktan and have been in absolute LOVE LOVE LOVE ever since. It's the same idea as the Moby, but without the tying. I love that you can put baby in while sitting, like if they pass out while you're sitting down or something, and take them out too. I have three of them now (well, they're all loaned out) and will probably get another with this baby too since my oldest two are a size small and my newest is a size extra small and fits better than the other two. You definitely want a tight fit, so size down if you're in between sizes.
Here is Dd3 in the extra small Ktan at 2 months old.
https://i1053.photobucket.com/albums/s465/oursnoopydog/bk1.jpg
And in just half of the small Ktan a little older. You can tell that it's kind of too loose. And obviously only half of the Ktan isn't safe. I keep my hand on them if I only wear half, usually it's just while I'm sitting.
https://i1053.photobucket.com/albums/s465/oursnoopydog/bk2.jpg
I also make ring slings (to give away locally) and I like it too. I didn't start that until recently though, so aside from trying one out with #1 when he was brand new, I haven't used it with a newbie yet. I don't like them laying down in any carrier, I prefer them to be upright, so that's what I'll do with my ring slings too. And for making that myself, I prefer medium rings over larges since I feel like a large takes up too much space on my chest/shoulder area.