I have to disagree with that. Douglass is now dead for 8 years, and though the publishers do periodic revisions by someone every few years, there is much information in them that is a decade or two old. Waggoners is also not up to date, but typically more so than Douglass. I have both, in many editions. The Douglass guides are in their 3rd or 4th edition in 20 or more years, Waggoners is revised yearly.
The Douglass guides are much more detailed in their coverage, including many smaller bays not mentioned in Waggoners. But the Douglass guides are also written for the more experienced audience, Waggoners more for the neophyte. One Waggoners covers the entire area from Tacoma to Skagway, this is spread across 5 or 6 Douglass books.
If you do much travel in the area, you will eventually want both, but in my opinion start with Waggoners.