I also did a lot of reading, after getting one as a gift when Willow was born. Basically, they shouldn't be in the cot under 6mo or before baby can remove a cloth from their face (most can do so by 6mo). I would put Will's in her cot for day naps so that she could get used to it, I also used to have it under my clothes so that it would smell like me and hopefully result in a better nap. I didn't put it in at night until I was convinced she would be able to take it off her face if needed.

My research said it was fine to be there under 6mo if baby was well swaddled, but ours was such a wiggler until we used sleeping bags instead so I didn't feel comfortable with that idea.

Now we absolutely love love love the comforter :)