Frankly, it tastes just like white cauliflower, although someone who prefers broccoli to cauliflower claimed it reminder her more of broccoli. But I'd lay odds that it is more nutritious than the white, because there so often is a color/vitamin relationship.

What's really fun is if you slice it up and dress it with an acidic dressing. The acid causes parts of the inner surfaces to turn bright magenta!