This is the best CR book out there. Though pretty similar to Manhattan GMAT book, it offers more practice questions in the book and has a slightly better overview of the Critical Reasoning questions.

~~~ Strengths: ~~~
1. In-depth overview of the Critical Reasoning strategies and approaches to questions
2. Clearly divides the CR question types and provides specific strategy for each type as well as the pitfalls and common errors. You will also get to know how the CR questions are made.
3. Good quality GMAT-like practice questions
4. Created by the authors of the best LSAT books (LSAT logic section is much harder than CR on the GMAT; there is actually a decent amoount of overlap in this book with the LSAT book). Speaking of which, for extra hardcore (and absolutely not necessary but still), you can get the PowerScore LR book (comes with quite a few LSAT questions)

~~~ Weaknesses: ~~~
1. Could use more practice questions (more than mgmat though); you will need to find another source of CR questions such as GMAT Official guide 12 or the verbal supplement to the Official Guide (though the verbal OG has questions on the easier side)
2. Some explanations are too convoluted
3. No tests or online excercises/additional content


~~~~ My Suggestions ~~~~
- Read explanations to every question. Even if you got a question right, it does not mean, you solved it correctly (that is you used the correct approach or found all the shortcusts). You will be surpised sometimes and will pick up helpful tips even from explanations of questions you answered correctly
- Follow the actual strategies (DUH). This is probably the most common mistake people make - they start inventing their own approaches. Don't do it until you have a high verbal score. If you don't, just follow!
- If you don't have any Manhattan GMAT books, you want to get at least one, as each comes with access to 6 online CAT tests (these tests are worth the purchase). There is not a whole lot of value to get both Powerscore CR and MGMAT CR; the content is by large the same.


Good luck on your GMAT!
BB, Founder of GMAT Club
GMAT 750 (q49, v42)