Definitely a helpful book, clearly explaining all of your options and different factors you should take into consideration. The main issue is that this is rather geared towards the US market (fair enough), which means that some parts are a little irrelevant, especially the whole chapter on tax. However, most of the principles are applicable across different countries (or at least here in Australia) - Don't trust your feelings, invest in index funds, etc. It has helped me get a move on in my investing path.
The book is good for a passive investor who doesn't want to spend time researching stocks and is patient enough to wait decades until retirement and old age to get some wealth. Also it is a complete sales pitch to buy certain funds
However if you are planning to spend time researching stocks then this book is not of much use as it pushes you towards mediocre returns and perhaps wealth that might be created when you are old and retired. It exalts the efficient market theory and that is BS because market presents lots of inefficiencies from time to time to make great investments. This has been confirmed by great investors like Benjamin Graham, Seth Klarman and Buffett.
If you are looking to passively invest, re-balance once in a while and create wealth by the time you are old and retired then go for this book - else NOT.