Overall, this was a good read -- especially for existing programmers who are looking more at ADO.NET for things like architecture, usage, differences with ADO 2.x, etc... The book greatly simplified ADO.NET in my mind, and gave some great starting points in my own research.
My only problem with the book is that there are quite a few errors in the text that, in my opinion, the editors should have caught. For example, if you're new to OOP, you'll probably want to know the difference between overloading a method and overriding a function. This book on several occasions uses one term where another should have been used and vice-versa.
Overall, however, this is the best book on ADO that I've read so far...
_howard