They make considerable amount of torque, which is what really moves the car. With proper exhaust piping the torque made with 500 turbos will be comparable to my 16G turbos. Look at Seb's dyno of 500 turbos for reference.
On a highway you'll see the difference in power, but from a stop light, that sport500 car will move just as quick as a TD05-16G car...probably upto 60~80mph.