Josh,
I'm in a similiar situation to you (potentially upward mobile Rega owner) and decided to stay with the 10X4. First, the 10X4 is a great cartridge for the music I like (including much rock!). Also, based on what I've read, one's vinyl rig investment should be biased towards the turntable, then the arm, then the cartridge. You know, get the foundation right or you won't be able to maximize the cartridge potential. I've cheated a bit and upgraded the arm (Origin Live modded RB250), but my next step will be to buy a Nottingham or Teres TT. After that I'll think about the cartridge.
Good luck,
Beez