Brent, unfortunately, they did not have a powerful pump. The large openings were because there was no filter so if crap was in the water, it could usually blow through the holes. GE used openings similar to old KitchenAids, but GE had no filter and the motor only turned at half the speed of the Hobart, plus the pump had large tolerances since again there was no filter. In the deluxe front loading version of these early models with the blue vinyl racks, there was a piece of trim on the front of the top rack. It was a metal strip faced with some plastic bar on the front that had General Electric or something written in the plastic. The lack of filtering was so pronounced and the water pressure so weak that when Consumer Reports tested the machine, it repeatedly accumulated food between this piece of trim and the inner panel of the door. They recommended removing the trim piece. The pop-up tower did not wash UP very well; it washed OUT to the side, so pots and pans in the bottom rack would block the area above them in the top rack.
When GE did go to the smaller holes in their wash arms, they were not in the middle of a dimpled down area around the holes like in KA's 4 Way Hydro Sweep. They were just flat holes punched through the metal. The dimples around the smaller holes in the KA wash arm force the water to go up and to spread a bit. The water is under very high pressure to begin with, but the KA engineering of the openings makes the spray more effective without the GE's penchant for tossing things with just the brute force of the water. The flat holes in the GE just shot thick streams of water up and they had far more potential to break glasses and send small things flying. I remember that in the early 70s, some of GE's wash arms had all of the holes on one end of the arm and the opposite end just had one slanted jet to make the arm spin.