Before I was given Donder's book, I spent many a hour pouring over the encyclicals of JP II in my studies. With this book, I find that I am able to enjoy the encyclicals again. Although I do not recommend it for research or study, I do think it is a great book for those who want to know what JP II said in his encyclicals.
Could it err on the side of transliteration? Probably, but the heart of the message is not lost.