I ordered both Learning Language and Loving It and It Takes Two to Talk. I highly recommend both books and found them very useful. My 3 year old son's speech therapist spoke highly of the Hanen method and recommeded that I read It Takes Two to Talk. I am so glad, however, that I ordered both books because I found the more extensive discussion in Learning Language and Loving It to be very useful.
Learning Language and Loving it is directed to preschool teachers who are interested in supporting the language development of their students, while It Takes Two to Talk is focused on parents. However, Learning Language and Loving It contains most of the information included in It Takes to To Talk and much much more! An important part of learning to talk is speaking with one's peers and for speech delayed children this can be very difficult. Learning Language and Loving It gives tips on fostering peer interaction and has an extensive discussion on this topic. The book also includes information on different speaking styles of children, the stages of early speech development and how to help children best navigate through those stages. It includes useful information for more stages of speech development than It Takes Two to Talk (It takes Two focuses on the earliest stages including language discovers, early communicators, first words users, and combiners, while Learning Language expands the discussion to include early sentence users and later sentence users).
It Takes to To Talk is a great book and I recommend it. However, if you are interested in doing all you can to support the needs of a speech delayed child, I recommend that you also consider Learning Language and Loving It (another Hanen Method book).