I've been teaching on and off for 12 years across most of Asia and I've got nothing bad to say about these books. There are some teachers who feel that this set of books is out of date and somewhat irrelevant when teaching in Asia. I couldn't disagree more. `A bad workman blames his tools'. If you're a contentious and focussed educator, it really doesn't matter whether you're teaching something relevant to yesterday or ten years ago. These books are invaluable in teaching and practicing the 4 skills as well as grammar, pronunciation etc and are organised in a progressive and informative way. Well done Headway.