All depends on how good you are with the material going in I think. I got it done in 1 to 1.5 months. Is the stuff relatively fresh in your mind? Even if it's not, if you did well in your courses and grasped the material relatively well, content review will be a lot easier. And I agree with Rolling that it's good to mix up the review because, as I'm finding right now through practice tests, the test is big on integrative thinking. It'll help if you're already making a lot of connections in the content while doing the review.
Content review is important... your goal should be to have a very good conceptual handle on the content before heading into practice exams. But practice exams are where everything starts coming together... they really help reinforce the material and hone your thinking for the MCAT.