I love my kozy carrier. I purchased it for my first child, who is now 8. I've most recently used it for my littlest child, who is a few days shy of her 1st birthday. 8 years of frequent use and it still looks great! I was able to babywear in this from birth by rolling the bottom up slightly, and used it a ton when my son was a toddler, even up to 4 years old I could comfortably carry him on my back in my kozy. I also run a daycare and have used my kozy for wearing infants in my care over the least 6 years I've been open. It fits very well in my diaper bag.
I'm a a plus sized mama and the straps on my kozy were made a bit longer for me as well, which has worked out great for me. I was even able to back-carry my daycare littles while pregnant!
There is a bit of a learning curve with the kozy, as with any baby carrier that is a wrap or needs to be tied on. I didn't find it too tough to figure out, and I just needed a little practice to be a pro.