I got access to these tests by redeeming my reward points and these tests are a real beauty.
On the quant side, there are ample amount of tests available covering all the question types and the solutions are discussed properly. The best part is that in discussion, if you find anything difficult or if you face doubt, you can check discussion and if your doubt is not discussed then you can go ahead and post your doubt, you will get answer for it in a couple of days by some expert for sure. And believe me, these tests are sufficient for quant preparation.
Verbal is good if we talk about the collection of questions but if you see it as a test then it is not very well structured. You will get all variety of questions but the distribution of them in real exam will not be like the one present in these tests. You might see here RCs with 5 questions which is not at all possible in GMAT. Other than that verbal is also a promising part of these cats.