Going against the trend in the thread so far here, but I honestly don't think these things are that helpful. Sure you can practice a little, but the PILAPT and COMPASS tests are designed to test your core skills - if you don't have the capacity in the first place you're never going to have it. I'd say that the only thing they can help you with is familiarity, therefore on the day of your assessment you know what to expect, but in terms of helping you get better at the tests, I think their effect is somewhat limited.