The Sybex Complete series are based on a novel idea of "adapting" chapters within existing books and combining them into one.

In particular, for C# Complete, chapters where taken from;

1. Mastering Visual C# .NET
2. Visual C# .NET Programming
3. Visual C# .NET Developer's Handbook
4. Mastering C# Database Programming
5. Mastering ASP.NET with C#
6. .NET Framework Solutions: In Search of the Lost Win32 API
7. .NET Wireless Programming

Undoubtedly this has it's draw backs, from the readers point of view the most annoying is the repeated explanation of topics as there is no synergy between the authors (an obvious enough statement as each group of chapters is taken from a different book).

The great benefit from the Complete Series is that you get the best chapters from the chosen books and a taste for the "complete" subject.

The book feels like it was produced cheap and cheerfully, inside though has been formatted consistently with large block titles, pronounced icons for emphasizing certain points and grey scale graphics where appropriate. Giving it a nice though-row touch, to such a point where it is not noticeable that this is an amalgamation of books.

You're not going to find anything special from the Complete Series, the chapters are taken from mainstream books to ultimately produce a book for the mainstream developer market. What you will get is a great mixture of material on a subject.

Personally, I will buy a Complete Series book from Sybex from now on when I'm first learning a new technology (and an O'Reilly's Nutshell a month later) and after reading I'll benefit from knowing which direction within a subject I want to explore about more.