Need Advice on Preparation Sources to Score 750+

Hello, rahuzuce, and welcome to the forum. A 750+ is not an easy target, even if you were already scoring around a 680 on an official mock test. Such a score would be quite an impressive baseline, however, and many such students with hard work and dedicated practice do end up in the range you have outlined. I, too, am more of a book learner than an online-module type, so I get it. With that said, I will address your questions below:

It can be adequate, or you can make very little headway in terms of genuine understanding. It will be important to focus on qualitative study over quantitative study. If you approach the task as if you must put in your two hours each day, then it will become a task, a chore that you dread. On the other hand, if you practice some questions one day, come back to the ones you missed on the next, and take the time to follow the reasoning behind where you had gone wrong and what makes the incorrect answers incorrect, then you can set yourself up for success the next time you might see such a question. Keep a thorough Error Log, and be honest with yourself. If you missed a Quant question because you overlooked the word positive in positive integer, thinking you had the question in the bag, then take note of it. Perhaps the next time, you will be a little more careful when combing through the keywords of the question stem. Also, find ways to integrate different types of problems to keep yourself engaged. Do not set aside four days in a row just for Quant and then switch to three days of Verbal. Your Quant might suffer during the break, and your Verbal might suffer on the Quant days. Keep at each portion and look to make incremental gains, focusing on content as well as test-specific technique.

I was able to carry on a private conversation on this topic with a Manhattan Prep instructor, who assured me that the new guides were just as good as the old, only in two larger books instead of spread out among ten. In other words, the older set is the standard for comparison, not the newer set. If you already have some of the older edition, then I would just add to them.

A little-known or discussed secret is that you can hit that mark without any additional guides besides the OG. To be clear, this is not a course of study I recommend for most test-takers--the GMAT™ is a tough nut to crack. However, some students who start out at a higher level just need a lot of exposure to official questions and a plan of attack for how to study those questions. You will never feel fully prepared to take the test, but if you start to score around your target range on a consistent basis using official material, then you will have some confidence in how you will likely perform on the actual exam. My short answer: if it gives you peace of mind to work through harder questions, then by all means, knock yourself out. Just make sure you center your prep on official questions, which have a unique "feel" to them, or all your training might not prepare you for what to expect on the real test. Manhattan Prep material is top-notch, but make sure you practice what you learn through your guides on official questions. Caveat emptor.

For Quant, especially advanced Quant, I find the GMAT Club questions to be of top quality. I am not saying this as a puffed-up designer of such questions--I wish I had written a few--but as someone who has dabbled in the material and read many debriefs from top-scoring students who have written that they found the same. Some students really like the PowerScore CR Bible for that question type, but I would use it only if I found my form lacking after having gone through the Manhattan Prep material. Finally, to supplement your OG, make sure you check out the discussion on any questions of interest. The amount of top-notch input from both Experts and community members alike is staggering, and reading through it for questions you missed or had trouble with will certainly help you gain a better perspective on the matters at hand. It is like getting advice from a tutoring team instead of just one person or source, and sometimes one point of view might resonate with you more than another.

Good luck in your preparation process, however you decide to go about it. Keep us posted.

- Andrew