I received my copy of this yesterday (from greatmodels.com- funny, somehow a Tamiya F16 was in the box with it...)
At first glance, this appears to be a great reference book.
There are a bunch of new photos, not the same old rehashed stuff seen in many of the references that are out there. The included maps are awesome- there's even a separate map for "Operation Deadlight" showing where all the Uboats were scuttled after WWII. Illustrations are very nice- color pates (artwork, not photos) showing boats wtih camo, some of the crests, etc. (lots of type VIIs, but also Type IX, X, etc.)
Lots of stuff on midget subs as well. I have barely scratched the surface on this book, and I'm really impressed by how much is shown. It's pricey, but so far I think it's a really good book.
what were once vices are now habits