One raised bed was the site of my experimental Phacelia tenacetifolia cover crop / layered mulching trial. The other raised bed is much sandier and has had mulch added and dug in with no cover crop. The cover crop area is naturally much more clay-like. Water has been on the same soaker hose, though the sandier soil gets the far end of the hose and the clay soil gets the near end, if there's a difference. But look at the difference in productivity! These pumpkins were planted at around the same time with seeds from the same package.
Clay soil with cover crop wins by a huge margin!