I tried the free practice test and found that Veritas Prep's version of GMAT mock exam was delicately written to conform with the "logic" behind the real test. I had a pleasant test experience; the platform was easy to navigate and the solutions to each question showed a detail analysis of all answer choices.
As good representatives of GMAT questions were scarce, I decided to purchase a package that contained 6 additional mock exams and took 4 of them. After those tests, I would say that although the questions were great to practice with, each mock had its own concentration that didn't reflect the reality; for example, there could be a string of difficult questions or a particular area might be overrepresented.
However, as we can only find the next best GMAT questions from a small number of prep providers, Veritas Prep's ones are as good as they get.