The mere fact that this guide is now in its 20th year is evidence of its popularity. It is unquestionably the most successful guide of its kind. Much of that success lies in its clear if sometimes oversimplified listings that make it easy for rank beginners to find the majority of popular watches, and the sheer volume of entries. I would rate the pocket watch section over the wrist watch listing for detail (e.g., coverage for high-end watches like Patek, Rolex and others is superficial and buyers should rely on some other book), but both are adequate for the most popular material.
However, evidence is that most of the prices are not updated annually, and publishing deadlines make the few updates old when fresh off the press. Some prices simply remain untouched for years when auction and other sales clearly show significant changes (generally increases). I wonder how many of the scarcer and "by-the-book-mint" watches the authors would be willing to sell from their collections for the prices shown?
Some historical information, such as the production dates and serial numbers are questionable. The section on Aurora watches is clearly at odds with documented factory records despite fresh editing done to that information in the 2000 edition. And where South Bend individual grades are priced in detail, Auroras are lumped into general groups -- a sad oversight, since many of those grades are very scarce (multi-stars). Other rather common grades from popular makers are unexplainably missing amid a hit-and-miss grade list.
The price grading system is dramatically skewed to the unobtainable, making one minute flaw justification to slash the price below half of its near-mint state (which is mint minus a box, yet most watches likely never had factory boxes). Certainly mint watches deserve a premium, but the book's definition of mint is toward the absurd, and extra fine is nearly unobtainable. The result is that most seller's simply redefine the grades. It would be better if the author would make that adjustment, which would also put prices in line.
And the insistance that all watches still be in their original cases? That likelihood vanished sometime during the Great Depression, when even a gold-filled case could be swapped for silveriod to pay back a few dollars, never mind how many solid gold cases vanished into pawn shops. The presence of other screw marks in the back of a case for anything short of a perfect mint watch is closely akin to the flap over used postage stamps mounted in albums with hinges: much ado about nothing.
Finally, the foreign pocket watch section has only about 75 maker's price lists, and they are highly generalized. While something is better than nothing, perhaps this guide has become too long in the tooth, relying on minor annual tune-ups when a complete overhaul is due. But it sells, makes money, and there is no incentive to enter a new effort. Unfortunately, I cannot recommend anything better, except to get out and see the real market for yourself.
In the meantime, treat it as a general guide, but seldom if ever the final answer - one that even in it newest release is actually behind except for items that have not changed prices in years (not many of those). Even the generalized empty case prices show no adjustment for gold market or demand, and can sit unchaged from one edition to the next. That should be your first clue something is amiss.
Perhaps one problem here is the modern world of Internet auctions, which appear to be totally ignored as a basis for market sales histories. It would additionaly explain why this guide increasingly becomes outdated, even if it is published each year, having failed to see a whole new arena of buyers and sellers. Being the only one of its kind annual guide clearly accounts for most of its success. Perhaps a truly timely price book covering 90% of what is in the market simply is not possible . . . at least not quite yet. When it does appear, I will be first in line for a more accurate reference. Until then, don't make this is your only watch pricebook.