Only edition on which one can rely on to get the unadulterated and pure message of Lord. Where the market is bamboozled with the various editions of Gita, none of those are devoid of mental speculations and personal opinions of the author.
That's why, Srila Prabhupada establishes this fact, at the very beginning of the book.
So why should you read this edition of Gita and not others? Because this edition of Gita is
"As it is"
Here the message of Lord Krishna has been conveyed without mixing the author's own political, and social opinion.