Tower of Visions is similar to the usual Porcelain Tower event, except it has different enemies and only 20 floors + 2 EX floors.
Crimson Saber is also not available in the event's mog shop, so the rewards are mostly visiores, summon tickets, and other materials.
Enemies in floor 1~10 are fairly easy to do in full auto, but floor 11+ are filled with enemies that have high resistances to most things except their elemental counterpart and 1 attack type weakness.