Blades are much more efficient. I've done some back of the napkin estimates that this would levitate if paired with lockheed's supposed small fusion reactor. (a

Blades are much more efficient. I've done some back of the napkin estimates that this would levitate if paired with lockheed's supposed small fusion reactor. (and works at all, and if the drive reaches improvements that one paper thought possible, and if it scales with power input, and ....) This inefficiency would still be great in space because you don't have to carry reaction mass with you. (and hovering on earth would mean sustained 1g acceleration in space, which is fantastic.) But if you're swimming through reaction mass anyway, then just push it as efficiently as possible.