sub-frame connectors do more than prevent frame twist from engine torque. They add a great deal of structural integrity to the unit body reducing shakes and rattles, and provide a more rigid platform for the suspension to work from so it works better in everything from drag style launches to corner carving. IMO, they are just as important to improving handling as a Monte Carlo bar, export brace, and shock tower reinforcement.
"It's not having what you want, it's wanting what you've got!" - Sheryl Crow