Having a counterbalance can reduce the required holding and lifting torque & current but increases the mass which the motor must accelerate for downward motion and so increases lowering torque & current.
Ideally any counterbalance should be about tuning the system, as Jazz said the motor should be up to the job of holding if correctly rated.
Counterbalancing is a widely used technique in industry to allow systems to deal mainly with motive forces, to minimise static forces and to improve safety by ensuring a system doesn't move out of control in the event of power loss,

- Nick