While I have not taken the LSAT exam personally, I have used Mometrix study materials and was very pleased with the results.
I took the GRE following my last semester of college in order to pursue graduate studies. I decided not to attend graduate school at the time and to pursue a career instead. Five years later, I decided it was time to earn a graduate degree. My GRE scores had expired and I had to re-take the GRE in order to apply to another graduate school. Using the study guide and flashcards from Mometrix as my ONLY study resources, my overall test score on the GRE was 200 points higher than it was immediately following undergraduate graduation!
All of this played into my decision to take a position with the company 3 years later. The main reason I decided to work for Mometrix was because of how much their study materials helped me prepare for the exam. I wouldn't want to be a part of selling a product I didn't believe in.
No study resource will work unless you do, but the study guides offer helpful study tips, practice questions, and in many cases they include complete practice tests. The flashcards are in a question and answer format to help you understand the underlying concepts the test questions will be based on. If you aren't pleased with the materials, they offer a one year money back guarantee.