One odd thing: the reference layout has worked well enough for me that I haven't felt the need to read from cover to cover, because the index & table of contents & occasional apt cross-reference almost always put me in the 1-5 pages that answer my question. I browsed another STL book in the bookstore today & wondered, why haven't I come across so helpful a description of user-defined iterators in Josuttis? When I got home, now with question in mind, I found the same information in Josuttis within a minute. I can readily imagine advanced users having questions not addressed in Josuttis, but at present his succinct STL pitfall flags, cautions & workarounds pretty much keep me from STL grief.
OK, so intriguing design concepts are not what this book is about; but the efficiency and thoroughness mean that his writing style is not plain, it's lucid *smile*.