So just how important is the bench? I have noticed a lot of cement benches, do they need to be that sturdy? What would the difference in group size be between a wood, portable, or cement bench. If a guy can shoot say 1 inch at 100 on a portable bench, how much better can he expect to shoot from a cement bench with a XYZ rest. How would you compare a lead sled shot from a wooden picnic table. Now same conditions same rifle from a cement bench quality rest and bags.