Pros:
Very well written, easy to read. Rather thouroughly documented. Sufficiently illustrated. Academic in the sense that year-long accepted "truths" about Schumann's (mental) health are questioned and challenged. After reading this book I think you have a good picture of the life (and death) of Robert Schumann.
Cons:
It's a tricky business to "diagnose" people deceased centuries ago, only based on diaries, doctor's comments, etc. (what was the level of medical expertise in Leipzig in the first half of the nineteenth century? Some of remarks by several doctor's seem to have been taken at face-value) Although Worthen makes well documented assumptions about Schumann's health, there remains an element of uncertainty and doubt. After all, you never saw the "patient"...
At times I find the book too apologetic towards Schumann. His social skills seem to have been under-developed(creating, on a personal level, problems with visitors, but also on a professional level with choirs and orchestras). Some of his works were not that great, especially some larger-scale works. For these, and other, aspects of Schumann (and his works) Worthen tries hard, but in my view not always very convincing, to find reason's and excuses. And why? Even if he wrote some lesser works, even if he wasn't very social, he is still a great composer of eternally beautiful music.
Also, at some points there are some odd remaks in this book, e.g. when Clara had a miscarriage it is stated that she was not too sad about it (at this point I would have appreciated supporting documentation). Also, the statement that Schumann was the first composer to compose for his children struck me as strange: J.S. Bach e.g. wrote Clavier-Büchlein for his son Wilhelm Friedemann Bach (among other works for his other sons).
But still, 4 stars, because when you're interested in the life of the great composer Robert Schumann I think this book is one of the best available. Despite the critical remarkts above I found it hard to put this book down.