Being able to ramp the best land out of the top four cards of your deck at instant speed is already very useful, but the fact that you can still draw one of them into your hand as a fall back means that you wont have a major downside (see Growth Spiral for a similar effect)
Not only snow lands, which we desperately needed more of anyway, but also other snow cards, including instants
The circular ramps are in a self-contained area of the toolbox with high bumpers to prevent the balls from jumping out of the ramps
She uses her magic for evil, casting hexes and sewing chaos in a world that never seemed to want her
The short answer is that in general you get a reasonable amount of value over a Raven's Crime, both information and disruption, however there is a significant delay on the relevance of that disruption
As a card, it's solid, letting you flood the battlefield with copies of Assassins in exile with memory counters