I personally don't mind advice on parenting...even if it comes from someone who hasn't actually raised their own children. Some people have a heart and understanding of children that supercedes the parenting experience.
If parenting knowledge is limited to those who have children then heaven help us as there are is sea of dysfunctional parents raising children and their claim to fame is "that's my child" and or "it didn't hurt me and I turned out fine!" The Ezzo's jump to mind immediately for creating great havoc within the Christian community.
Like you, I sit up and listen when I admire the children of a particular family. I am always curious as to what they did and how. But it only makes up one part of the picture. There is a lot of psychology built into raising a child well. Obviously, our home situation and our own childhood history plays an integral part...but as adults we have to be open to change in our own pre-conceived ideas of parenting.
Understanding how our children learn both intellectually, spiritually and emotionally into strong, healthy human beings is an ongoing process.I must also add that I find it refreshing to find a Christian book that doesn't promote, encourage and abdicate physical punishment as the biblical way! I will gladly read a refreshing take on Christian parenting that supports my own parenting philosophy and what I believe Jesus wants for my children.
From there, I try to learn and do better as my children change and grow and if that is from a book written by someone who may not have their own children...well, I will keep that in my thoughts as I weigh what they have to say.