And don't forget the most important thing. Hijack seems to be ever-growing in its feature-set.
About the only thing I could suggest with the basic info is to break it down a little for people who aren't familiar with computers/car audio and the various jargon-based names to be able to more easily digest it.
In this respect, it might be nice to expand on what each of the features mentioned does. Not full descriptions with instructions or anything like that (you cover that later). But for instance "VolAdj" can have some additional text that explains what it means. Or maybe don't actually include the names at all for the features, but just English descriptions of what they do. I find it easier to use jargon/technical descriptions too, so I can't offer suggestions at this late hour.
And for FTP you may mention that it's for transferring files to/from the player disks and might as well mention "web" along with "HTTP"
Hijack can be overwhelming to any user. Just keep in mind that after installing it, it isn't going to immediately do anything you don't want it to do. You will still have the same player experience until you decide to start exploring its features. So go ahead and install it and then read the FAQ as you play with the different features. I think a good place to start is by exploring the Hijack menu (most of its power comes from outside of the menu interface in my opinion and that's all covered in the FAQ)
But in general, it is a
"low-level upgrade to offer a varied selection of user-controlled advanced features." Yeah, it's a mouthful.
Lastly, it's pretty safe using Logo-Editor to upload/flash Hijack to the player. Wiping Hijack and restoring your player software if needed, without hurting any of your music, is as easy as uploading a fresh .upgrade file. (serial connection for both)
Bruno