We’ve only used this carrier once, but so far we give it 5 stars. It took us a while to properly adjust it so our 8 month old baby was not sitting too low, but once we did, she fit well and she didn’t seem to be uncomfortable! She enjoyed being able to peek over her dad’s shoulder to see ahead, or look side to side. I did not notice any red marks or areas where the pack/straps rubbed on her skin. Some of the straps even had protection. If it had been warmer outside, she probably would’ve gotten quite warm and sweaty, and the sun cover didn’t provide as much shade as I’d have liked, which is my only design critique. When I wore the backpack, I realized I was leaning forward a bit while walking but my husband did not have the same issue. Otherwise, we loved how adjustable everything is, we appreciate the pockets for storage and detachable bookbag, we were surprised by how lightweight our daughter and the pack felt, we LOVE the kickstand feature, and we like the look of the design. We’re glad we went with this version.As an FYI— Check the pocket in the sun shade for the rain cover.