Hi All - I want to share my G Day and preparation experience. As a summary I have given the GMAT two times within a span of 2 months.
GMAT 1 - 620 (Q48, V28) and GMAT 2 - 720 (Q50, V38):-D :-D . I prepared for 5 months because of a full time consulting job (Average 10 hrs everyday) and used an array of prep material
Prep CAT Scores1. GMAT Prep 1: 730
2. GMAT Prep 2: 720 (I found this the most accurate!)
3. GMAT Exam Pack 1: 740 (In my opinion, The Exam Pack 1 is definitely easier than the actual GMAT; the algorithm gives you more levy to make mistakes and the questions are easier)
4. GMAT Exam Pack 2: 740 (When I gave this test, the level of questions that came up from the question pool were comparable to the GMAT, except Quants which was easier)
5. Manhattan CATs (1-6 in order): 610, 640, 630 ,680, 680, 700 (These tests are tougher, especially from the timing standpoint, but are great for practice)
6. Veritas Free Test: 710 (Although I found the algorithm comparable to the actual GMAT, I found weird verbal concepts tested in this test. Give it a shot if you have time!)
7. Economist GMAT: 660 (Cannot comment much on this exam. I was not fully focused during the exam)
8. Kaplan Free Test: 730 (Irrelevant i would say. I had 19 mistakes in verbal and still managed this score) :-D
Material Used (Self Study only):1. OG and Verbal Review
2. Manhattan SC Guide (By far the best book on SC - A must have. I read this book almost 3 times)
3. Power Score Bible for CR (Must Have - Great Techniques)
4. Manhattan Quant Guides (5 books - Excellent for basic concepts)
5. GMAT Club Maths Book and GMAT Club Free Tests
6. Bunuel Tough Questions Bank - All in One with solutions
7. GMAT PREP Comprehensive CR, SC and RC - PDF with all retired GMAT questions. Excellent source for practice
8.
Error LogMay'14 to Jun'14: In this initial phase I gathered material and feedback from folks who had already aced the GMAT (700+ experiences). I took the diagnostic test to identify my strengths and weaknesses. Coming from an engineering background, I was comfortable with Quants and realized that most of my preparation should be revolving around verbal concepts. I started by reading and simultaneously making notes from the Manhattan SC guide and Power Score CR Bible - I would suggest to thoroughly read the SC book, at least 3 times, whereas the Power Score book can be skimmed through if you are able to grasp the CR solving techniques mentioned in it. After feeling confident in theory, I attempted verbal questions from the OG - My practice was mostly timed and spread through only 2 verbal sections: SC and CR. I also had access to the 6 Manhattan tests and gave two of them during this time. Got pretty low scores in Manhattan, but did not delve too much into it and continued my preparation. Towards the end of June, I gave my first GMAT Prep Test 1 and was satisfied with my performance. One thing to note and probably something you should not repeat: I did not practice RC and Quants during this time. It is imperative to practice all areas that contribute to your GMAT score to get the holistic picture of your performance in any mock test.
Jul'14 to Sept'14 (GMAT 1):I spent this time practicing questions and revising concepts. I completed OG and the Verbal Review. I also completed the remaining CAT's during this period and practiced some of my mistakes. The only major drawback was that I didn't maintain a thorough
error log and was not able to get to the depth of SC concepts. For SC, it is very important to read explanations from experts. This will help you justify your elimination of an option even if you ended up getting the correct answer. I felt confident the night before my GMAT exam! I had studied extremely hard to raise my level, especially in verbal, and felt that I would nail the GMAT. However, fate can be cruel at times. I gave the GMAT the next day and completely bombed it!

:(. My heart sank and I couldn't believe that I ended up with only 620! (Q48, V28). During the exam I felt the verbal section was very easy and I was acing it. However, after I gathered myself after a few days I realized that there were two reasons for my failure. Strategy and Extra Pressure/Expectation from the exam. Basically I had psyched myself to a great extent before the exam and put unnecessary pressure on myself to perform well. I realized the greatness of the GMAT exam - Along with Quants and Verbal it tests you on parameters actually required during an MBA such as strategy, decision making, personality attributes and so on. The exam format and questions are a medium to do that. I realized that you need to be extra careful at the start of every section (Without dedicating too much extra time - Its a trade off!) and need to have a clear head without preconceived pressures of performance. Additionally, I also knew that SC was my weakest section and I needed to practice in smart way and learn from my mistakes
Oct'14 to Nov'14 (GMAT 2): I had to travel to the US for work and did not study anything during that time

. I used the trip to self introspect about my strengths and weaknesses and motivated myself to give another shot at the GMAT - I could not let so much of preparation go down the drain without breaking the 700 barrier! When I returned from the US, I booked my GMAT for the next month. I focused primarily on verbal during this time and only practiced official questions! The change to my pattern of study was that i researched the negation of every option in a SC or CR question. I also polished my RC skills by doing at least 3 passages everyday. I also changed my attitude towards the GMAT and did not take performance pressure. I also just gave the 2 mocks during this time - The GMAT Preps and scored 750 and 740 on them. These scores might be slightly inflated by 20 points due to a repeat attempt, but i don't think so

I had also carefully decided on my timing strategy for each section and planned to stick with it during the actual GMAT. Personally, I believe you need to extremely careful at the start, although some books claim that this is a myth! Finally my second G day arrived and I was actually feeling very relaxed. I didn't do anything out of the ordinary to feel relaxed, unlike my first attempt where I was forcefully listening to music and all those sorts of things

. So getting back to the GMAT, I skimmed through AWA and IR conserving maximum energy and took my break. The Quants section started off with a couple of easy questions, but the level exasperated suddenly and I got a string of tough questions which made me very nervous. A line of Probability and P&C was not something I was used to seeing. However I looked at the positive aspect and thought that maybe I was doing well and that is why these tough questions. I wrapped up Quants right on time and took my break. Feeling relaxed I jumped into verbal with only one thing at the back of my mind - Don't skim through questions in a jiffy, be careful at the start and negate a option only when you feel confident. Luckily I did't have any timing issues or major hiccups in the verbal section and boom! 720 flashed on the screen! I felt enervated - Something that i wanted so badly and worked so hard for since the last 6 months was finally here. I had crossed the 700 barrier. My split with a 720 GMAT was 50Q, 38V, 7 IR, 5.5 AWA. Probably I could have done better by 20 points, but I was extremely happy. A 100 point jump in just 1 month was amazing! I am unsure if I would give the GMAT another shot to stretch my score in the 740-760 range, but at the moment I am just happy that my hard work with so much parallel work commitment has paid off!
P.S. The overall GMAT experience was wonderful. GMAT Club, Ron Purewal from Manhattan, Buenel and all other sources I mentioned above are simply awesome!! :-D
Cheers!