I can conclusively say that gmat club tests are the best for quant as well as verbal preparation. Quant section is pretty exhaustive with 24 tests - I can't imagine any other prep having that much volume of queations. Quant questions are of high quality and you can certainly feel the difference after taking the same. Solving and revision of the same should take through the quant section thoroughly. the quality of Verbal questions is close enough. Though compared to quant it is not as exhaustive and in some of the tests the balance between SC, CR and RC was missed. Therefore I would request the makers to add more content. Overall the test platform is pretty good and worth the money!