Verbal for Gmat is very different from the verbal on other exams such as GRE, CAT(Indian B-schools). Within the few months, I exhausted all the resources including Manhattan books, Official Guide. However, I was not able to reach a verbal score of even 30.
I had read reviews on the Gmat-club about E-Gmat verbal course, especially for non-native speakers. So for the final push in my verbal preparation I decided to purchase the verbal online course of E-Gmat.
Review of the Verbal Course->
Master comprehension-: 5/5
Critical Reasoning: Did not use.
The master comprehension section & Sentence Correction are stand-out among them as they focus on the very basics which are needed for cracking the Gmat.
I did not find RC material to be much helpful and did not have time for the CR material but have heard that it's also very Good.