It was helpful for me, but the baby book was certainly handy. I had thought DS8 was a level 3...until I pulled out the actual dates when he did things...

The use of early milestones is one of the criticisms of Ruf's work, BTW. But there is plenty in there that isn't so early, too.

It's just one more way to tell what's going on, and I tend to think that we need all the tools we can get. If it isn't helpful to you, try something else.

Kriston