I'm not going to go into definitions of each type of carrier. That would make two already long posts even longer, and the definitions are easy to come by. Babywearing International has excellent definitions; so would a simple Google search. I will focus instead on the carriers I own, and what I have found helpful (or not) with each one. I'll also briefly touch on the types of carriers I don't own, and what I know about them.
Also, it's worth saying that I have never mastered the art of simultaneous babywearing and nursing. I know plenty of women who do, but it's just never worked for me. Either my shirt or the carrier would always get awkwardly twisted, and I would have to take the whole ensemble off and start over. I gave up early on. But it is possible to nurse while wearing virtually any carrier. Some even double as their own nursing covers.
All right, let's start with slings. I love the idea of slings--they are super easy to use, and relatively un-bulky. I had the advantage of "trying out" a sling with my niece for several years before having my own child. She loved it, and was always happy in her sling, but I could get tired easily from having all the weight of the carrier on one shoulder. I knew a sling wouldn't work for me in terms of lifestyle babywearing. Then I had Peregrine, and I soon found out he just wasn't a sling baby. Something about the scrunched-up position required has always rubbed him the wrong way. I've seen so many babies so completely content in slings. Peregrine never was. That said, I own two slings, and they have seen their fair share of use.
What I don't love: Peregrine was rarely ever comfortable in it past a few weeks of age. Even during those first few weeks, positioning him just so was a pain. Also, it may look hands-free, and it is, but if you're wearing it correctly, your shoulder is pinned down. It's great for shopping and washing the dishes, but not for reaching up high and putting things away. I always forgot that when I put it on.
Pouch slings are not adjustable, and that means that if anyone else is going to wear your baby, they will probably need a sling of their own (length of torso matters more than anything, but so does your chest measurement). This sling fit both Andrew and me until I washed it. Then it got too tight for Andrew. I ended up getting him a bigger one (it is worth noting here that Seven Slings, the company I got it from, has occasional amazing deals where you pay only shipping and get whole slings for free. This is how I got Andrew's.)
This is my ring sling. I scored it at a thrift store for $10. That was a good day.
What I love: Anyone, of any size, can wear it. That, and its portability, makes it a great option for taking to (or leaving with) a sitter. Also, it is the only carrier I know that you can put a child to sleep in and then remove from your body, with the child in it, and put the whole package peacefully to bed. This is a huge advantage. Most babies go to sleep easier in carriers; some (like Peregrine) have stages where they don't take kindly to going to sleep anywhere else. He would sleep in bed, it just took forever to get him to sleep. Enter, the ring sling. Swaddle baby, insert baby into sling, rock/walk baby to sleep while doing something else, wait for baby to sleep, loosen rings, remove sling, carry to bed, and voila! Peaceful nap! If he fell asleep in any other carrier, I was stuck with him on my body for the duration of his nap. Which sometimes I didn't mind, but sometimes I did.
Once Peregrine could sit on my hip in this sling, he liked it a lot better. I still wear him in it this way, especially when he is sad or sick. It's his preferred snuggling position, he can still see my face, I can even keep my arm around him--but my hands are free and I can get things done.
What I don't love: I am still trying to figure out the ring thing. My sister-in-law, ring sling wearer and expert extraordinaire, has shown me how to do it multiple times, but I've never fully gotten the hang of it (oddly enough, Peregrine liked slings a lot more when she was wearing him). And the one-shoulder thing wears on me after awhile, way more so than with the pouch sling. Once I mentioned this to my midwife, and she said that often, it is men and stronger women who tend to be most comfortable with slings. I have a very weak upper body. Maybe that's the explanation.
Pouch slings and ring slings are the main sling styles, but they come in all sorts of fabrics. I saw a lady recently with a pouch sling that was stretchy (mine isn't at all), and it looked quite comfortable. Some ring slings have padded sides, which can be snuggly and soft, but can also pose some suffocation risks when the baby is incorrectly positioned. I highly suggest trying to breathe through the fabric of your sling, just to see if you can. It's generally suggested that you avoid the "bag" style of sling (you can google it for pictures; I hardly ever see this style used anymore).
All right, moving on to wraps. This was the type of carrier my midwife suggested I try when I mentioned disliking having all the weight on one shoulder. Wraps distribute the weight evenly over both, and some of the weight rests on your hips as well. I have much stronger hips than shoulders.
I have a Moby Wrap, and I cannot believe I don't have a decent picture of it. I wore that thing daily. I guess it often happened when I was home alone. Andrew is wearing the Moby in the picture in my previous post, but you can't see it at all.
What I love: I love my Moby wrap. It is my favorite carrier in terms of comfort, and the one that most approximates the feel of "wearing" a baby. Peregrine actually really liked it, and I didn't mind him taking whole naps in it because it was so comfortable. I loved it for walking him outside, because my coat zipped over it--no need for a coat or extra bundling for Peregrine, just my coat and body heat. So easy. And once Peregrine's hips and legs got stronger (around four months, I think), we could wear him facing out, and suddenly, Peregrine really started to like being in a carrier. It was short-lived, because soon he could start reaching for dangerous items, but it was nice for awhile. Peregrine was not an easy baby to make content. Excited, yes. Content, no.
I wish I had more than one, and with a successive baby, I just might invest in another. Peregrine spit up a lot, and since the Moby covers such a large area, there was no way to keep it clean. One good wet burp, and it was unwearable. I always wished I had a spare.
What I don't love: It's kind of rocket science, wrapping it correctly. Once you know how, you can do it in about a minute or so, but even then, get one piece wrong, and you have to start all over again and adjust it. Which means removing the baby. Which may not sit very well with the baby. (Also, I recommend not doing the initial instructional-video-watching while your baby is screaming. Just a suggestion.) My experience was that it is very difficult to get too tight, and very easy to make too loose.
A few other things worth noting: the Moby wrap traps body heat like none other. Which was great for me, but I am very cold-blooded. If I got overheated too easily, I would hate this carrier.
Also, I know some friends who have had chunkier babies who don't like the Moby as much, and say that the stretchiness makes it less supportive with a bigger baby. I didn't use it past about six months with Peregrine, because that's when he started liking the ring sling better, and started being more content away from my body. So I haven't had experience using it with a heavier baby. Apparently woven wraps (non-stretchy wraps) are a lot more supportive. I don't have one and have never used one, but they are fairly popular. Their huge advantage over the Moby (and the reason I will be stalking thrift stores again if I have another baby) is that you can wrap a baby (even at a very young age) on your back. Housework is worlds easier with a baby on your back instead of your front.
Well, that wraps up part one. Part two will be arriving shortly.