This is a great little board to keep around the shop, especially if you find yourself tinkering with a Pi frequently. The only thing I would say is to not use it on a key chain, as the PCB is fairly thin and I would be worried about it snapping if placed in pocket. But all and all, a great little reference tool!
This cheat sheet is a good idea. For my eyes, I would like to see a bit larger font. I bought extras for a friend as a gift and he thinks it's a great idea to be able to move the reference board to other Pi's.
My son had previously completed a couple of simple soldering projects, and thought these would be a good way to show what he was learning to his grandparents. He was able to complete 4 of them with almost no help. Great little kit.