They're not in RO mode while synching but they are while driving. If a drive is in RW mode then as data gets written to a disk it doesn't necessarily go straight on the disk. It can be cached which means that potentially that data will never get written if the unit is powered down without warning. Since basically nothing ever needs to be written while driving/listening then this is not a problem. However it does seem the player must mount RW some times when it saves things like the plays counter and the seek tool info. I'm not sure where this data gets saved.

In the case of a PC this generally doesn't happen since when you shut down all this cached data is written to the drive. In the case of the empeg, the ignition can turn off at any time without warning. Imagine having to shutdown your empeg every time you go to stop your car...

I think you may be thinking that RW vs RO mode means that the drive can't be damaged. In terms of the drive it doesn't have a RO mode. It's the filesystem that does all the RW/RO stuff. Edit And technically Windows is in RW mode 100% of the time. It doesn't have a RO mode.

Does that it explain it well enough?