I put my daughter to sleep in this more than any other pajama, soft and thick and warm and comfy. Being in Southern California it typically doesn't get too cold but this winter has been colder and her room doesn't get warm at all as it gets no sun all day. She stayed nice and warm in it on our trip to Texas over Thanksgiving, for reference she was 11 months old. Pic included is from that holiday trip after I came home early and left her with Dad and Grandma otherwise she would be wearing socks on that cold tile! ;)This has worn well, I bought it when she was 9 months old and while it doesn't fit her long legs at 13 months she is still wearing it and it fits with the exception of her legs although her Dr just told us she is at 97% in height so she is very tall for her age. I feel it runs big but I feel that is a good thing for baby wear since they can outgrow everything at this age very quickly. I've washed it a lot since she wears it a lot and no complaints here, I do use Dreft detergent for her.Sometimes I leave it on her and she plays well in it, runs around and crawled in it when we first got it, no wear on the knees for that brief time. And well this thing is absolutely ADORABLE, what baby will not look super cute in it!I will DEFINITELY be buying this again, one of my favorite Amazon buys and the price is great IMO for the amount of wear I got out of it!!!