Starting in March? When's your test?
Mine's on Wednesday, and I got Qbank at the beginning of Jan. I started with the occassional small test here specifically testing what I studied. Once I got through the first round of everything in First Aid and review books, I just began doing 50 question tests on everything. I scheduled it out so I have 150 questions every morning, then spend the rest of the day reviewing. I wouldn't see the need for going through it again, though I'll touch up on some sections where calculations are needed, just to trim it up a bit.
Personally, I find the Qbank questions to be somewhat picky at times, and every once in a while find one that's contradictory and has two answers. I can only hope that's not the case on the real deal.