I don't think that the other books would be inconsistent with "How to Talk... "
it's just that How to Talk will be looser than 'when your kid does this, do this' type books.
How to Talk is not a book on discipline, it is a book on interpersonal communication, triggers, reasons kids (and spouses) turn off their ears and ignore us.... I loved this book and I do think it's worth buying, just to have on hand years down the line.
For me, this book was a real game-changer in how I worked with my preschoolers and I utilize the concepts in this book nearly daily. What I love about it is that it really helps parents of older (five and up)kids help their kids figure out how to solve their own problems through opening up those conversations to their ideas as well as our own. This also allows the children to take ownership and investment in their own solutions to regular challenges, which is less 'doing to' our kids and more of a 'doing with' approach. This does, sometimes, challenge us as parents to let go in some areas and however, I have found that sometimes our kids have unconventional solutions which work for them (ones we as adults might not have thought of) and resolutions better all around.
I think the other piece of this book I appreciated was the focus on the child's internal reality. This book opens kids up because it guides the parents in giving active validation to our child's ideas and feelings.
For what it's worth, I think 123 Magic and Love and Logic are both very effective, but just want to warn that we still want to parent authentically, and there will be times when following the book for the sake of following the book is actually counterproductive in our relationships with our kids. And consider getting the book copy, as there are fun little 'comic strips' of how their techniques are utilized; I found that I used a lot of sticky notes to mark pages, etc.