I'm so glad you love our 5-lb GRE guide! We developed that guide in large part because the Official Guides for the GRE contain far fewer practice problems than the GMAT official guides (and there are fewer editions of those OGs). We wanted our GRE students to have the same wealth of practice questions that GMAT students have with the OG. So for that reason, we haven't felt the need to develop a 5-lb Guide for the GMAT (at least not yet).

There are numerous questions by topic in each chapter of our strategy guides. However, the best way to prep for the GMAT is by practicing questions from the OGs.

If you've gone through the OGs already but aren't seeing the score improvement you want, more practice questions won't help. You need to deeply review and analyze the questions you've done.
- use Navigator or a similar tool to track your progress by question type and topic
- keep careful record of your mistakes in an Error Log
- redo problems you've done before and make flashcards for takeaways
- time yourself while you're practicing so you nail the timing on test day

Good luck!