This has been perfect for my newborn. We bought it on a whim, and it was so marvellous have just bought another one so we can have one in use and one in the wash!
It is very simple, unlike swaddling blankets, and being able to change a nappy without removing it (using the two-way zipper) is incredibly convenient, especially during those bleary late-night changes.
The baby is very comfortable and cosy (and looks incredibly cute); it stretches to allow a some arm and leg movement, but is snug enough to stop the Moro reflex waking her up.
Don't bother with any other kind of swaddle, this one is highly recommended!