This is my first merino wool sleep sack. I've used the fleece ones (with full sleeves) in the past but always felt like my child was getting too warm. I got this one for a 2 month old and have not been disappointed. I wish it would dry quicker after washing but overall, this has been a great product.Pros:- warm for baby: I've used a onesie or a footed sleeper, depending on how cold the night will be but each time, my baby has remained comfortable and warm without being hot. also, the Merino Kids website has a temperature chart which give you an idea of when the sleep sack is most helpful.- easy to get on and off, even while baby is sleeping. The zipper is very smooth and the buttons on the shoulder snap quietly and easily and are very sturdy. Once you undo the shoulder and side buttons and zipper, it opens almost completely flat.- the cut-out for the seat belt buckle is a dream come true. I have to drop off older children in the morning and its the easiest thing to pick up my baby, plop him in the carseat, and zoom off. Also, because its not bulky, I don't worry about the car seat straps being too loose in the event of an accident.- color is vibrant.Cons:- The time to dry the sack after washing it.- The price-- its steep but at the same time, I use it every night.