The functionality of this thing is just as described and works well. My wife really likes it, has it on her desk and uses it all the time. She's a meditator so maybe that's why she likes the concept.
I personally would say it's better for kids; The reason being that the water dries up and doesn't stay there for a long time, you can't dedicate enough time to a drawing. Hence you wont be involved enough, or appreciate your work enough, or get attached to it enough, to be able to really experience and practice "the art of letting go" as they say.
Also, I thought it would have a slab of rock sitting on the thing. But it's more of a plastic look, and it bends and what not. I think they should've made it thicker and not cover the back with black plastic either. So people could just turn it and start a fresh and don't have to wait for it to dry (although it's a good practice for patience and observing).
All in all, I think it is absolutely great for little kids, or even more dedicated older kids, or a doodlers like my wife.