Excellent for reviewing concepts you've understood a while back but have since gotten rusty on.  Just the right level of detail.  If learning for the first time, other books that spend more time illustrating/motivating the concepts might be better -- can't say for sure as I'm not in that position.  But for reviewing, it's great.  The book fulfills a definite need by bringing in one place the mathematics most relevant to ML, and going through it in a concise yet precise manner.