I am considering purchasing either the px400 or the 300. I have a couple of questions about the features of the px400.

I tried them both out in a noisy shop and the sounds do seem to be the same, but the PX400 is supposed to have more sounds. The sounds are more accessible on the panel, but it seems to me that the extra sounds are just duplicates of the GM sounds. Are there differences that I just wasn't hearing?

I use a Mac, so I guess USB file transfer is out (no driver from Casio), but it seems that I could still transfer files via the smartmedia card. I don't know much about SMF (simple media file) format. Is it the same as .mid? Will I be able to transfer performances on the Casio to my sequencer for tweaking and what-not? Will I be able to transfer songs of my own devising to the Casio?

Any comments would be appreciated.