3d mark 2000 is heavily t&l biased, it's like compairing apples and oranges using something that's biased against apples.
Which one you pick mostly depends on what games you play, do you play Q3 or UT? Do you play MDK2? What about Deus Ex? If you play UT and Deus Ex allot, then get the V3. If you play Q3 and MDK2 allot, get the MX.
If you've got $120, get the MX, if you've got $60, get the V3, or wait a month and get the MX.