I found preface of the book more interesting than the text. The text is actually a translation of 18 Gita Chapters in English.
At times, the translation is little difficult but overall is easy to follow. If you know/read/understand a bit of Sanskrut, would be easy to read Sanskrut Chapter and then read the translaton to judge the quality yourself.
This is a good book for those who do not know Mahabharat story. The reason it is good for the beginners is that it is concise and flows through the subject quickly. So it would be a good book for new readers who can quickly get a sort of overview of Mahabharat.
If you already know Mahabharat plot and story, try and get a little advanced book.