Very easy to grow. Pretty to look at, half purple and half green. Extremely easy to propagate by cuttings. A taste that is halfway between parsley and seaweed, which leaves me conflicted. Okinawan spinach has strong medicinal properties. But, I am a huge fan of the taste of parsley - like I could eat it all day - and very much someone who gets nauseous at the taste of anything fishy. So I find that I can't manage to eat more than 5 leaves of Okinawan spinach at a time, and not cooked in anything.
So for me it's a good supplementary plant. But for someone who enjoys Japanese food/sushi for instance, I can imagine this being very enjoyable. I could see it being great as an alternative to seaweed in a sushi roll with avocado and some sesame seeds, if you don't mind that it also kind of tastes like parsley. I have considered using it in broths as a fish sauce substitute, since I am vegetarian, but I rarely have need for that kind of flavor so have not tried it yet.
It's reasonably drought-tolerant, but so far I have not had any lucky growing it in local soil. It seems to only grow in the rich organic soil in my pots. But since I eat so little of it, that hasn't really been a problem.