They are pretty comfy for a couple hours stretch! But be aware that the K'Tan is really only supportive enough until baby hits about 15lb. After that baby sags too much, so the carrier won't provide enough support. You don't want baby's bottom to sag past your belly button. The sizing is pretty wonky too, so try before you buy. The carrier should be tight to you before baby goes in. Learn more about the different types of carriers at TheBabyWearer forums or BabyCenter's Babywearing Group.