Artist mode is one of those things I learned from Bernt Hansen’s excellent Organize Your Life In Plain Text! introduction to Org mode. I’ve used it in conjunction with ditaa to produce simple but finished block diagrams from ASCII diagrams.
I haven’t used it for so long that I’d pretty much forgotten about it but then I came across this excellent video from Rob Rohan on using artist mode. It takes a bit of practice to get as fluid as Rohan is with it but it’s not really hard.
A Rohan points out, artist mode is also useful for adding diagrams to your source code comments or other places where the ASCII art is good enough or even preferable. If you’re like me, you probably won’t use it all that often but sometimes it’s exactly what you need. It’s especially nice in conjunction with an Org mode code block where you can have it produce a nice diagram for your output while keeping all the source in your Org mode source file.