For what its worth I quite like the Van Tharp book, although I'm not entirely sure about the books true agenda. The relatively inexperienced will probably fail to see or dismiss the very few words of wisdom the book offers, whilst the more experienced will find Tharps treatment of the subject matter rather lack luster and lacking in detail.
Its quite clear that the books underlying agenda is a marketing tool for further products and services, its very firmly aimed at those who've been about a while but haven't got it figured out, and are therefore susceptible to his pitch. Nevertheless the book has at least a reasonable back of a fag packet types overview of how you might go about getting your ducks in a row to develop a strategy, but its nothing that isn't freely available or much better presented elsewhere. Despite its faults its still a book I'll occasionally dip into.
Temptrader hit the nail on the head really, Its well known that Van Tharp does not trade, nor is he actively involved in systems research, and the book certainly reflects that, and I guess thats why many dismiss the book, in my view perhaps unfairly.
Tharp and Robbins are basically repackaging fundamentally sound concepts, and delivering them in a consumer friendly fashion, targeting I suspect very similar markets.
Take my advice, yachts are for sailing, not trading on.