mandark1709
Which OG is better for Verbal? I used the OG 17 but a lot of people have advised me to use OG 11 or OG 12
OG 11 and OG 12 will overlap with EP1 and EP2 (slightly but they do and more so with OG 10). There is obviously also overlap between OG 2017 and previous editions, so the value of going back is there only if you have done all GMAT Preps and Exam packs. Otherwise, you will be inflating your scores.
P.S. Keep in mind that you want to use questions as target practice after studying a certain topic, not just as "let me take a random question and learn from my failure" That's a much harder way of studying and quite inefficient one as well - it only works for those who are already scoring quite high and need to fill in gaps to move from 720 to 750.