It's been a while now that An Enemy We Created has been out now. You can get it from all decent bookshops, as well as on kindle (finally), both in the UK and in the USA.
The reviews that have come in have been almost entirely positive. You can read clippings and mentions and browse through the full list over here.
I was invited to talk at the University of Oklahoma (Norman, Oklahoma) and at Creighton University (Omaha, Nebraska) where An Enemy We Created is being assigned as required reading for some courses. The students had many (many) questions and it was great to be able to interact with an audience that had read the book.
If you haven't had a chance, perhaps take a look next time you're in a bookshop. It's about a lot more than just the Taliban-Al-Qaeda relationship. You can read some excerpts from the reviews over here.