I will be sewing until about Dec. 15, and will then be closed for the remainder of the year. Please keep these dates in mind if you think you'll need a sling for a holiday gift. If you are sending a wrap for conversion, please do not ship after Monday, Dec. 16 -- I will not be sewing during my break and would prefer not to have things pile up too much. I may need to stop WCRS ordering before Dec. 15, depending on the workload that's built up before then; I will post on Facebook if that will be the case.
I've been making slings -- and only slings -- since 2001.
There are a lot of sellers on eBay and Etsy now, many of them using the same pleated design I've been using since I started (and for which I offer free sewing directions, for personal use, and have done since early 2001).
What's the comparison?
Well, the prices may be similar (usually mine are lower) and the fabrics may be the same (I was the first to offer tencel twill, for example; and linen is a favorite amongst many sling wearers and sewers). But I feel that my years of customer service and troubleshooting make SBP a better choice than what may be a brand-new startup, where the maker in question may not be able to answer your questions about wearing your sling, or may not have considered the mechanics of how a sling is sewn.
For instance, the further away from the rings the first seam is sewn, the less the shoulder area will be able to spread out. The wider the pleats, the more unmanagable the shoulder can be, cutting into the wearer's neck and flowing over her arm. The narrower the shoulder area is, the less you'll be able to spread it out. I've put a lot of time and testing into my slings, so you can rest assured they will fit most women correctly. I've seen a number of slings where the sewing is so far from the rings, even the seller is unable to wear the sling correctly -- the fabric ends up all bunched up by her neck, or in a 4" area on top of her shoulder. That's not comfortable in the long run, and can be unsafe as well -- if the rings have to be worn low for the wearer to be able to spread the fabric over her shoulder, there's less room for the baby in the sling, and less fabric around the baby's body.
Does the seller offer original directions? If not, it's likely they haven't fully considered how to help when a customer has a question about how to use a sling. It's my experience that in order to tell someone how to use a sling, you have to know it inside and out yourself. You have to have worn a sleepy newborn, or a heavy, struggling toddler, to really be able to troubleshoot those situations. I'm on my third "sling baby" now, and have years of experience with a wide range of ages and stages. If you email me, I'll be able to help. Will you get that kind of help from someone who is copying another company's wearing directions? Who knows. And of course, the photos used in their listings will tell you a lot -- are they even using their own slings correctly? If the rings are down near their ribs and they have to hold the child to keep them from falling out; or the fabric is all bunched up by their necks, they probably won't be able to help you wear a sling correctly or comfortably, either.
Sewing (and wearing!) slings can be a safety issue. When you buy something that will be holding your child, you want to know that it's going to be safe. Is the seller using adequate fabrics, or just something they got cheap at WalMart? If they're using thin cotton prints, are they in a single layer (one hopes not!) or safely doubled? Are they using safe rings? Sometimes they will say; other times, it's left to your imagination. And it's not something that a lot of manufacturers like to talk about, but it is important: are they insured, in case the worst happens and a child is injured in one of their slings? If they aren't insured, both parties are in for a world of hurt.
Finally, if you don't want to take my word for it, please go read the ring sling reviews at The Babywearer. Click on "reviews" at the top of the chart to sort by the number of reviews, and see who comes out on top :)
Of course, some Etsy and eBay sellers are reputable and do sew safe slings and can help you use them. I don't want this to sound like I think all of them are universally bad, because they aren't. But you need to be able to tell which are which, and examining the photos (or indeed, the lack thereof) can tell you a lot. Here are a few Etsy sellers I recommend: Babyette (she's a fantastic woman and a lovely seamstress), SnuggyBaby (shoulder is very wide, but the slings are quite nicely-sewn), Obimama (for gathered-shoulder fans), and Baby Pockets (neat shoulder design and they look very well-sewn). SweatPea slings are also very well-sewn, but she's not on Etsy anymore.
Good luck, and safe babywearing!