BTW she was a mystic too... I don't find their particular brand of Christianity Scriptural either. Not a big fan of the Holiness movement, either
this was an interesting article on Smith:
http://www.pfo.org/hwsmith.htm
I'm going to read it more thoroughly, but I think there are some valid points in there. If I remember correctly though, she did not fail to emphasize holiness. And when she said God was to do the work, not us, it meant He did the work THROUGH us. And this book is all about AFTER you accept Christ, so there is no lack of faith first. And no absence of the doctrine of sin and the need repentance. But still, there may be some truth to some of the criticism. It's been too long for me to say.
The article overall distorts the book (I remember it well enough to say). Smith never said you would be happy because things were grand. You'd have trials. But she was teaching how to be happy through trials, how to understand that God has something to teach you through them. When you recognize that, when your faith is in God alone, you can be happy under all circumstances -- as Paul said that he was content with much or little, to die or live, in jail or free....
Smith, in her book, talked of difficulties she had, like the lady that drove her crazy until she realized God wanted to use the lady to teach her patience. She also talked about difficulties concerning sin. She never claimed to be perfect.
This book was just about changing the Christian's attitude and outlook. Happiness in this context would be better described as Christian joy, which is a fruit of the Spirit. We aren't supposed to run around being miserable, are we?
The Universalism and mysticism stuff in the Henry book is weird and totally contrary to the Smith book I read.