Mizumi is a reincarnation of Okada. If you're familiar with Okada, then Mizumi will be no surprise to you. The food items are the same as before so there are little differences, save the name and decorations.
The sashimi is still fresh as ever and the grilled items are cooked perfectly.
My favorites included the lobster sashimi, the uni, the amaebi, the crab miso. If you're staying at the Wynn/Encore and don't want to venture out for food, this is a good place to eat at.