Sybyl FF followon

Before I get flamed for forgetting the underlying physics...
 Granted, the VdW term "covers" dispersion forces (which makes
 neg E terms ok), but...
 1) Is the force field able to "accurately" treat these - i.e. is the
    VdW cutoff a computational or a methodological requirement?
 2) What is a reasonable cutoff - the paper lists 8 A, but should
    this be lower/higher?
 3) Has the FF changed/evolved since the paper?
 *sigh* I guess I should check deeper into the library before posting...
 Joe Leonard
 jle[ AT ]
 P.S. The asbestos undies still fit... :-)