These are fantastic! We use them almost everynight with our two children. We like the lighter weight cotton for nights that are cool and the heavier fleece or velboa on colder nights. The kids sleep well in them and we sleep well knowing that they are warm and safe. Our babies stay warm because they can't kick off this blanket. They stay safe because they can't get tangled up or have their faces covered by this blanket. As far as I can tell, Halo is the only wearable blanket that is endorsed by the SIDS coalitions. I can't imagine not having sleepsacks. They are one of my favorite baby shower gifts to give. I think they are a must have item for all babies!