I think if your serious about your choosen breed and are looking to have show quality birds or birds that are true to what the standards says they should be, then it is worth the money to buy the current SOP. I have mine and am constantly referring to it when I am evaluating my birds. I just purchased a speckled sussex pair and the SOP was the first thing I turned to when I got home.
I also look at the other breeds in there and evaluate their colors. I love my book, and while it was an expensive purchase, I find it well worth the money I spent. I have been told repeatedly by various breeders, that if you are serious about breeding and showing, you need to have a copy of the standard.
Walt, It was a pleasure meeting you, congrats on your award.
Lanae