LOVE IT!!! The Deuter Kid Carrier II is the best carrier ever.
We have used it several times now, and it makes it really easy to enjoy your hike with your little one. You can use it probably upwards from 6 months ( they have to be able to hold their head), and our sons enjoys it soo much. He loves to look around, and seems to be really comfortable in it as he always falls asleep after a while. The harness and the area where the child sits/leans onto, is padded so it doesn´t hurt him but still keeps him tight in there. it has a ton of storage for diapers, snacks, beverages, and it also has a H2O department for your camelback.
THe shoulder straps are adjustable to the height of the carrier, so is the waist strap. they are all padded, too, so it´s really comfortable on your back and hips. It is not very heavy, even though sturdy.
It´s really easy to use, and you can get your child in and out very fast, so you can use it around the house or for short walks as well as for long hikes.