IMO, everyone needs torque boxes or subframe connectors at a minimum. Both are even better.
To demonstrate, while you car is in the garage, put a floor jack under the left front wheel and jack it up until that tire is off the ground. Continue going up until a second tire comes off the ground, then back it off just enough to put the second lifting tire back onto the ground. Now step back and look at your car. This is how much it can flex. Now try to open and close the drivers side door. This is why additional bracing is nice to have. This twist you have just introduced has nothing to do with horsepower. That is simply how much movement you car can absorb, which means under power, that is power is being absorbed by the car and not being put to the wheels.
Challengercrazy, if you car already has connectors in it, then no need to cut them out to put new ones in, just don't put new ones in. However, I suspect we are thinking two separate things. Subframe connectors are a boxed unit running parallel to the sill from the torsion bar cross member to the front leaf spring mount area.