I used mnemosyne, which is a similar program, and I kind of varied my strategy depending on the rotation. I think it's great for really driving home specific facts (vaccine schedules for peds, tests to order at different stages of pregnancy in ob/gyn, etc.) but I didn't have time to use it for EVERYTHING. My typical strategy was read X number of pages in a rotation-specific review text, make a few cards of the really high yield concrete facts, review some cards, go back to reading. I didn't really use it at all during surgery, I just didn't have time.
My goal was to keep up with ALL my cards from the first 2 years plus add on clinical stuff... yeah... that hasn't happened :-/