Which ladder standoff do I think is best for use on a shingled roof between the ACRO or Ladder-Max models?

SEE THIS REVIEW OF MINE FOR THE ACRO STANDOFF BY ITSELF:
   • ACRO Building Systems Ladder Standoff...  

SEE THIS REVIEW OF MINE FOR THE Ladder-Max STANDOFF BY ITSELF:    • Ladder-Max Model ABM 2002 Ladder Stan...