I am going against the Maya Wrap love fest here and recommending something else! My very favorite sling is the Didymos, I know it is pricey, but the Girasol or EllaRoo are excellent and somewhat cheaper alternatives. Why? Because they a just so versatile. Yes, they have a longer learning curve but once you get the hang of it, which takes you all of a couple of attempts, they are so worth it. You have the options of the cradle, wrap n cross carry when newborn, the cross carry, wrap n cross carry, kangaroo carry, hip carry and several ways to tie the sling in a back carry once they get older. I love how it distributes weight on both shoulders which makes wearing them in a sling for longer periods way more comfortable.
The issue I have with the Maya Wrap is to get the sling comfortable, many people can't get the rings postioned properly, ie coursage position, They often end up too low on the wearers breast. or even lower. The OTSBH is okay, but way too padded for my liking.
I have't tried a KK fleece sling, but I still think the Didymos/Girasol/EllaRoo are more practical in the long run because of their versatility.
As a complete sling addict, I have to say that the perfect sling doesn't exist it really depends on many factors: you, your baby, how and how long you wear your baby, what you like to do while wearing your baby and how much time and effort you want to put into it.