Joseph,
I don't know how the DRM 604 differs from the DRM 600. I can only say
that I have used the DRM 600 and I have been pleased with its performance.
I do have one caution. The DRM 600 is strictly a single user type of
CD-ROM player. It should not be used on a network server where two or more
people will be accessing different discs on the player at the same time. The
DRM has only one read station and shuffles the discs around mechanically when
an I/O request comes in for a disc not at the read station. It takes about 5
seconds to make the swap. If several people are accessing different discs on
the same player over a network, response time could degrade pretty quickly.
Phil