Arms-up or arms-down swaddle—which is better for a newborn?

It depends on the baby. Community consensus across r/newborns and r/beyondthebump is that babies who fight traditional wrapping and want their hands near their face often do dramatically better in an arms-up zip swaddle like the Love to Dream Swaddle UP, while babies with a strong startle reflex who need maximum compression tend to settle better in a structured velcro wrap such as the HALO SleepSack Swaddle. Many parents report buying one of each before they find the winner.