I have a Baby Bjorn I used with DD and I'm using it again with DS. DS is getting to heavy for it and my back hurts if I wear him in it too long. He's 7.5 months old and about 18 pounds. I need to wear him so I can do more things with DD and more stuff around the house.
Is it even worth getting a Moby now? I heard they can handle an older baby better than a Baby Bjorn...
Re: Is it too late for the Moby Wrap?
Chemical Pregnancy
If you are inclined towards wrapping like the Moby than you may really enjoy using a woven wrap. Think Moby but more supportive and not stretchy. I use one with my 7 month old and they are super comfortable up to toddler age and you can do both front and back carries. You can only do front carries with the Moby.
The ergo is also a great option as are mei ties and ring slings. You may have a local baby wearing group were you can try out other people's carriers.... Or do like I did and buy pretty much one of everything! Hehe
My go to carriers are my ring sling by sleeping baby productions and my woven wrap.
Think of it this way
Moby's encourage a snuggling sensation for newborns. They have "give" as they're jersey material.
Woven wraps don't have give, and are solely for the purpose of holding LO so you can be hands free.
I'd look in to a woven wrap since LO is above the 15 lb Moby limit. It's safer for baby, and will be more comfortable for you since it'll hold better.