In practice, the biggest difference between the book for Red Hat version 6 and the one for Red Hat 7 is the Red Hat distribution CDs that are included with the latter. It's an excellent way to get Red Hat 7, if you don't have the previous version of the book. Red Hat Linux 7 Unleashed is more useful than the manuals that are provided by Red Hat with the retail distribution. What you get here is 1,000 pages of practical information on configuring and using the software. For example, all of the chat clients that are supplied--from the original chat utility itself to ICQ and AIM--are covered in detail. More importantly, the Red Hat manuals basically cover desktop use, while RedHat Linux 7 Unleashed covers networking aspects such as Samba, Apache, NIS, NFS, network management, remote printing, and network security. Also, it goes into areas that the manual doesn't touch, including C/C++ programming, scripting, and building new kernels--to hit just the highlights.
If there's a downside to this book, then, strangely, it has to be the emphasis on the Red Hat distribution. For example, because Red Hat 7 doesn't include the excellent ReiserFS journaling file system, this isn't covered--if you want to use it, you'll have to figure out how to download, install, and set it up yourself.
Nevertheless, RedHat Linux 7 Unleashed certainly is the best manual that's available currently for Red Hat Linux 7, and a fount of hands-on information. --Steve Patient, Amazon.co.uk