Amazingly helpful and effective
MB is I think one of the best ways to learn Mandarin available, if not the best. The method does have a slow start as you have to learn the 'movie method' for remembering characters, but like learning to drive a car, once you know what you're doing, going fast becomes easy. The course is hand-holdy for the first bit until you're comfortable enough on your own to move through learning at speed, but once the training wheels are off, I doubt there is a faster and more effective method of learning mandarin reading, writing, and speaking simultaneously, and intuitively connecting them all in your mind, the way a language should be learnt.