Blue Crystal is playable in like a UB shell as a wincon in a box. While generally the crystals' discounts are almost totally irrelevant, a good UB deck is going to have a lot of Dreams of Laguna that can get the benefit twice pretty easily. Black Crystal is also playable, because the life-gain on its exile clause is actually pretty nuts. They're almost all worth considering picking in paper, because they're worth a couple bucks. Though if I was playing Arena, I'd still probably take Relm's Sketching over the crystal if I was already in U.
Drafting this set in paper is a little weird, because you're going to see expensive-ass Amano-art cards that don't at all work with what you're doing... but goddamn, they're worth a pretty penny. Other than red, the colors all feel pretty deep - the guy right next to me was drafting in the same archetype, and we both figured the other was in a different color pair.