Admittedly, Complete Scoundrel is a title that I've been anticipating for a couple of months now. Complete Mage was a superb follow up to the Complete Arcane (and for someone who does not care for arcanists, this was hard for me to admit). Perhaps my dillema with this book was that I was looking at this to be a sort of follow-up to Complete Adventurer. Sadly, it is not.
One of the things I have enjoyed about the releases since the Player's Handbook II was the alternative class features, but Complete Scoundrel entirely lacks this selling point. Instead we have the "Making a Scoundrel" section which offers class, prestige class, feat, and skill trick suggestions for different types of personalities. While this is a nice touch, most of the feat suggestions are from the other Complete manuals.
Most of the feats are directly set to the expected classes: Rogue, Bard, Swashbuckler, Scout, and Ninja. Several of the Ambush feats are recycled directly from Dragon Magazine #344. Despite the discussion that any class can display scoundrel-like tendencies, not any class can use these feats. To make up for that, we have the "Luck Feats," which provide an in-game way to do what many players may try to get away with at the table anyway: reroll a result you don't like.
The skill tricks are, as described in the book, like mini-feats that have limited uses per day. Each skill trick requires 2 skill points to learn, which is exceptionally nice if you have a character that's gaining 8, 6, or even 4 + Int modifier skill points on a level up. But again, your 2 + Int mod characters will probably want to spend those 2 or 3 precious skill points trying to permanently increase their chances of success on their more important class skills, rather than gaining a couple of 1/day special actions that most often require a successful skill check anyway. Flashy, yes, but universally available, no.
The Prestige Classes and the Organizations are perhaps the most interesting sections. The Combat Trapsmith has been long-awaited, and the Gray Guard - a paladin who has been granted the freedom to pursue justice by any means necessary - is a superb concept. The Master of Masks is like a theatrical version of the Tattooed Monk from Complete Warrior. Even the psions have access to a new personalized prestige class that meshes well with the Shadowmind from Complete Adventurer.
Very little love is shown for new items and spells. Perhaps we're still reveling from the Spell Compendium and awaiting the Magic Item Compendium.
All in all, it is my belief that a lot of this release felt like an extended section of the Class Acts from Dragon Magazine. Perhaps it was the high expectation I had after being impressed by Complete Mage. Perhaps I'm still wondering why we require at least 5 pages of every manual to describe the changes to polymorph and to define the swift and immediate action, especially if we're constantly being referenced to feats and prestige classes previously published. Complete Scoundrel seemed to define a scoundrel with an immensely broad definition in its introduction (imagine if Complete Divine claimed that any character who ever questioned the existence of a god was a "divine" character), but failed to live up to all parts of its definition.
Bottom line: Collectors should pick this one up. Anyone who wants to add a few flashy maneuvers for their diplomats or their rogues should pick this one up. If you don't already have Complete Adventurer, don't pick it up. If you occassionally let your players have a pity-reroll from time to time, don't pick it up.