When I upgraded to X11, I splashed an extra $30 for a printed manual and I am really glad I did. Just flicking through it reveals so many great features I had either forgotten about or overlooked in the past. It is so much easier to discover things from a printed manual than from a document on a screen. I've been making an effort to incorporate some of the newer tools and features into my workflow and it is really paying off in how much more quickly I can get some things done (shape painting), as well as how much I can get done in X11 without having to go over to Photoshop (masks).

I reckon it is the best $30 I've spent in a long time and I highly recommend it to everyone, especially if you are a long time user, like me, who tends to continue to do things the way they have always done them.