You know, Ive been asking this vary question... Things Ive seen written around the various mic postings is that the V63M is the same as the MXL2003. I looked at Mars Music and its "Special Mars Exclusive thingie" The V63M has a 1" dia, 6 micron diaphragm, tranformerless output. The 2003 has a 1.06" 3 microndiaphragm and low cut switch. Both have FET preamps, single diaphragm, cardioid and a black finish.
I ordered a v63m and should get it on wednesday, after a brief overview and inspection of the mic and its propaganda material I will attempt to enlighten the curious. Until then...
Peace,
Dennis