(~3.5 stars, rounded down)
I didn't like this book at all (though I did still enjoy reading it somewhat, because of the good company), as a book to learn functional analysis from. It has much to recommend it as a reference volume, though, and as a tool for review of this material, for someone who has already mastered it.
The book is less pedagogical than it could (should?) be, and that's putting it mildly. I cannot stress enough that THIS BOOK HAS NO PICTURES IN IT (which I don't know how to forgive). What it _does_ have is an impressively large and diverse array of theorems and examples. It also has plenty of exercises, but these come with little to no guidance, and no indication of their difficulty levels (which seem to vary unpredictably; I found most very challenging, though).
I frequently found my eyes glazing over, and a big part of that is probably because I was slightly under-prepared (analysis-wise) to read this book. I will probably find this book much more useful after I learn more functional analysis from more pedagogical sources, at which point a less negligible fraction of the huge collection of examples might become interesting and relevant to me.