4 point guarantee

I did already write Official GMAT couple of times. Being a non native speaker, and from a vernacular academic background, I was struggling with GMAT Verbal section. This was holding me back from scoring 700+. With my constant Quant score of 49 and highest V score of 34 in mind, I read about their 4 point guarantee. I was sold on that, as it would have taken me to 700.
With a couple of months prep I was able to score from V34 (my previous best) to V38.
I will highly recommend their Sentence Correction section. The lack of proper detailed explanations can't be ignored.
But in the end I got past 700 with my calculated risk with e GMAT.