I love DISCUS! I wish I had a big tank with Discus only. Perhaps one day
I agree with Gunnie. Sand must be much harder to clean than gravel. And if Discus are so sensitive to water chemistry, it's better to go with someting easy to clean. If you don't care about tank setup (i.e. how your tank looks), of course, bare bottom would be easiest to clean.
P.S. I am wondering: since Discus are so delicate, what water parameters are a must for them? Will they tolerate some
nitrate or not even that? And how large and how frequent water changes are necessary for them?