I have been buying these
I have been buying these for my daughter since birth in both the regular and warmer weights. I love that the material is organic cotton (not viscose or rayon) and the cut is generous for my chunky girl. Also love that the sizing goes up to a size XL!
On a side note, Burt's Bees customer service is amazing. I was initially sent a sleep sack with a seam coming undone and BB replaced it immediately when I contacted them. I will be a customer for life!