While it is definitely true that the ultimate way to optimise your study strategy would be through personal experience, which will involve making mistakes and will in turn allow you to develop more effective study strategies, there is no harm in testing this service, provided that money is not a concern, which I assume it won't be, considering their prices are rather low. They also seem to have a good reputation, as shown in their reviews, and the apparent collaboration with ICanMed. This doesn't go towards saying that a service of the sort is crucial for the development of an effective study plan/method, because that is simply not true.
I hope this helps!