I think this setting is critical for the 103R. If it is not set optimally, then it will sound like you're listening through a curtain. You will still get the great balance and timing that the 103R delivers, but not the considerable clarity, openness and focus that it can provide. This cartridge has a broad, deep and open soundstage with good perspectives of individual instruments - when set up right.
I just checked my 103R and it's currently set at 2.15g (this accuracy may be suspect, since I'm using the Shure balance, but that's as near as I can determine with it's scale). I suggest you set the VTF to 2g and start working up in small increments until clarity and focus is optimal. It appears to me like the 'sweet spot' in the magnetic gap is rather small - careful azimuth setting (if you have it) also yields dividends (as do antiskate and arm damping).
It's quite possible that the exact 'sweet spot' varies from cartridge to cartridge. Your ears are the best judge, but rest assured VTF does make a substantial difference with this cartridge.
