<p>I would recommend placing out whenever you can. Even if you will have to take more advanced classes extra. You will get out more from your MIT experience if you do that. You will actually learn new material. You will waste less time. The one exception I can find is 8.01/8.012, 8.02/8.022 dilemma (should I place out or retake). Since 8.012/8.022 is much more hardcore than AP physics, you might want to take those even if you got on 5 on AP physics. However, another strategy if you are fairly confident is to place out of 8.01/8.02, and take 8.09 /8.03/8.07, which will teach you new and very interesting material about classical mechanics and E&M, without the “hardcore problem-solving” involved in 8.012 and 8.022. My experience with 5.112 is that it raised more questions than it answered. Their approach is “We’ll use a bunch of Quantum Mechanics & Perturbation theory results without understanding it”. If you can place out of 5.111, and still want more chemistry experience (or you are scared of missing out), you should consider taking 5.03, which will answer many of the questions raised in 5.112.</p>
<p>Ironically, I would say 8.03, 8.07 and 8.09 are easier than 8.012 and 8.022 (despite being labelled upper level). That is because they de-emphasize problem solving and emphasize theory. So your exams will have a lot less time pressure. You might have to use more sophisticated math, but you won’t have to be as quick-witted.</p>