Can I classify my loops in folders on the card, or do I have to just throw them all in there together?

If you want to be able to import, the files will need to be in the root directory.

However, you can still name your samples in a smart way or add folders with back-ups.

Just realize you won't be able to import anything that's not in the root folder.

Correction: You won't be able to import anything that's in the root folder.

Place the sample in the X:\ROLAND\IMPORT folder instead. Refer to page 36 of the manual.

EDIT: You're right for the SP-404, PhemoX - the SP-404SX wants it in the ROLAND\IMPORT folder though.

So this means I'll be buying smaller capacity cards so I don't have to scroll through endless numbers of samples per card.