I've tried the following crosses with VS Black mains:
- CoFocus 17
- Focus Hex 18
- RPM Blast 17
- RPM Team 17
Team was a loser. Didn't last long enough. Hex and Blast were similar with both providing great control but neither lasted as long as CoFocus.
CoFocus doesn't provide as much control as the others but provides more spin, comfort, and durability.
In all cases I strung the mains in the mid 50s and the crosses in the low 50s.