The sleep sack really is great, the best I’ve found, I would give it 5 stars except there is NO perceptible difference between the 1.0 TOG and the 2.5 TOG sleep walker bags. I use the 2.5 and the 1.0 interchangeably and treat them both as a 1.75 TOG :). My toddler also doesn’t notice a difference and feels the same temp-wise in both.