benefit torque arm
Lower control arms keep the axle squared away front to back...
Torque arm keeps the driveshaft from spinning around the axle and cutting your car in half when you accelerate or break (slight exaggeration)
That being said, the torque arm isnt really going to pay off in terms of handling except to the very slight extent that it might help you plant the power better coming out of a corner and getting on the accel.
A torque arm's shining (or fatal) moment in the spotlight is usually the dragstrip launch. If you've got lots of power or are making preparation for lots of power and plan on doing hard launches on sticky tires, a torque arm is worthwhile. But for a bolt-on daily driver, I've found aftermarket torque arms to be an almost waste of money, especially the non-tailshaft mounted ones because of the interior vibration.


