Adobe Flex 4: Training from the Source, Volume 1

Well, I first have to said that I had a deep experience with Adobe Flex 3 in a advance project, now I bought this book in order to just get with Flex 4 new features, I would say that this book is a nice book for people newbies with Flex but my case I would wanted something more advance, hopefully the Volume 2 is for skill level. Still is a worthy book to have if you consider yourself as professional Flex developer or aim a certification.