Lecture Recording: MP3 vs. PCM

So this is going to be a small debate on what the best way to record is.

I just got an Olympus LS-10 for recording lectures at school, and I know there are about 20 different ways to record lectures (ie: different bit-rates, formats, etc.).

The three different formats I can run on it are PCM, MP3, and WAV format.

Obviously, WAV is the worst format out of all of them and PCM is the best (quality wise), but with the PCM format I lose "zoom mic" options which shouldn't be a problem. However, the sound quality improves tremendously (at least I would assume it does)... With improved sound quality comes loss of space... MP3: ~55Hours of recording... PCM (at max) ~ 4-6hrs.

So here is the debate: MP3 or PCM?!

Hope this is the right section...