I can't speak for the year 2000 as I was not doing
networking at this level at that time. But when I check the
specs for the base mx204 it says something like 32 VRFs, 2
million routes in FIB and 6 million routes in RIB. Clearly
those numbers are the total of routes across all VRFs
otherwise you arrive at silly numbers (64 million FIB if you
multiply, 128k FIB if you divide by 32). My conclusion is
that scale wise you are ok as long you do not try to have
more than one VRF with a complete copy of the DFZ.