One of the artists I admire (Caraid on Twitter, who did the covers for Silver Scales and Golden Coils) recommended it, among several other books/resources that I have not looked at. I cannot say if it is easier or better than other resources, since (a) I still haven't gotten around to using it and (b) I have not made particular use of any other tutorials either. So even once I get around to using the book, I would be a terrible person to answer this question. XD