they can be used, but as far as I know, the problem will be the navigation between the different folders that will take much more time as there can be much more folders on one SDCard. If you want to try them out, go on and do it, it sure will be an interesting experience. On BS3 and BS4, it should be ok, but on a BS2 I would stick to the max of 2GB, as the batterey would be down much faster with larger SDCards.
Music washes away from the soul the dust of everyday life. - Berthold Auerbach