That is the amazing aspect of Desert Aircraft, they are constantly performing tests on the motors, and more than manufacturing, they are like a lab,  they test, monitor, observe, improve!!  The benefactor of all this is the consumer.  Costs more up front, but you get a great product.  And if one day there is a problem, they will take care of their motor.  Imagine, they are so confident, they increased the warranty on their motors from 1 to 3 years.