I've listened to the whole series. The first book is VERY hard to listen to because of the hard things that everyone goes through and the horrible attitude of most of the people. I didn't like the first book. But it put things in perspective for this day and age and I realized it's not so bad in our time. The others were great and they helped me continue to realize all that God wants/has/ and will do through me if I let him!!
I throughly enjoyed both "A Voice in the Wind" (book1) and "As Sure as Dawn" (book 2). You'll not want to stop listening and be prepared to shed some tears. As well as learning a few humbling & moral lessons (something we can ALL use). Unfortunately I found "Echoes in the Darkness" (book 3) monotonous and unnecessarily long. Actually shouting "get on with it already!" a time or two. That being said, this would be a wonderful book-to-screen event.
If you love historical fiction, you will love all of the books in the series. They're pretty historically accurate, the author obviously put in the work to know about the geographical regions and religions in that time..