As you can see, this is seriously compact. The Bitybean purports to be a suitable carrier from newborn to 40lbs. I tried it out with two dolls of differing weights and a 14kg/32lb Audrey, and was pretty surprised.
With 6kgs of doll? Totally comfortable, easy to put on, no dramas. The body is not overly long and it's easy to position baby well for full knee-to-knee support.
Very surprised that the shoulder straps are quite so comfortable.
Flat shot - you can see the seat panel folds up and is secured over baby's legs with clips, because no one wants their small baby to fall out the sides. (instructions state that these MUST be used up to 15lbs, and that you can choose after this weight (when many babies would be sitting or have good core strength) to continue use or to place baby directly into the seat of the carrier, on top of the belt.
The bitybean is basically a trimmed down ssc - still very adjustable and with the safety features like a chest/back clip, which can be slid up or down the casing to adjust for best fit. I think having this properly positioned really helps those shoulder straps sit flat and snug.
As with all ssc, back carries need to wait until your child is sitting unassisted. This doll is 10kgs and I found it difficult to get high enough to be really happy. You can see that the shoulder straps are cinched to their limit.
I KNOW, I'm such a bad parent, her seat isn't knee to knee... And relax, because it doesn't NEED to be. Beyond approximately one year of age, the hips are formed and it's not imperative to keep an "M" position when wearing. It is often more comfortable for the wearer to keep the child's weight supported and close to the wearer's centre of gravity, but no one will die or be actively harmed by a seat that doesn't reach all the way from knee to knee.
For the parent who wants a carrier for their young baby and occasional older child use, or a spare to stuff in the nappy bag/take to the pool, this is a pretty nifty solution. OH, you can also use it IN the water, where it does a much better job than a water ring sling... Like any ssc, it's not infinitely adjustable, so you should try before you buy, but it does a good job of covering the essentials.