hey,
i took both medentry and the practice papers from acer.
the questions acer gives u in the practice papers are the EASIEST of the questions u r likely to face in the actual umat.
medentry will give u extensive experience with the harder questions.
i don't work for medentry, and i'm a bit of a tightass, so i don't say this lightly
but seriously, medentry is worth every dollar they charge. i cannot speak for other prep courses because i have not taken them, but the consensus seems to be, from everyone else i've spoken to who took medentry, that it REALLY helped them prepare for the umat.
btw i took the umat twice. first time:169 score- rejected from every school i applied to. second time- used medentry- got 204. accepted into 4 medical schools. (applied to 6- i was rejected by jcu which doesn't use umat, and umelb which has only 5 places for non-yr-12's).