I use Warm & Plush. It has no scrim & is 50% loftier than W&N. It quilts up beautifully & is still quite soft even when quilted at an average of 3/4" spacing (I prefer closer quilting because my clients are interested in heirloom quilts for their grandchildren). I would recommend at least quilting it every 2" so it will hold up for more than a couple years in the wash.
Wool can go either way. Some babies do better with wool; others are allergic/sensitive to it. The same thing is true with rayon (also marketed as "bamboo" or "bamboo rayon"). I personally don't use poly or poly blends for two reasons: (1) some of the little ones (3 and under) can have a hard time regulating body temperature with synthetic bedding, and (2) certain parents get panicky about anything other than natural/semi-synthetic fibers because if there is ever a fire, they will melt to the baby's skin. Of course, that's highly unlikely to happen ... but who am I to judge? So I now make 100% cotton quilts for the little ones: cotton fabric, cotton thread & 100% cotton batting with no scrim. But I made my first baby quilt with W&N, with that recycled plastic felt, and with synthetic rickrack. My nephew survived just fine. But I quilted it unevenly varying from 2" to 8" apart -- in the ditches -- because I didn't know any better, and after 2 years it needed some minor repair work to the stitching. I made one for my niece about the same time with W&N batting and quilted every 1" with a curvy meander & it's held up well, but I didn't like how stiff it ended up between the quilting & the fusible web applique. Since then, I do needle turn applique & use W&P, and I've yet to have any issues with stiffness. I quilt some areas as close together as 1/4" and some as far apart as 1.25", but with the W&P batt, it stays nice & cuddly soft and maintains a beautiful drape.