I've yet to get mine sub 7, and power to weight/ torque to weight suggests about 7.3 for the manual.
The IS200 loses 2 cylinders, 50 BHP and about 20 lbft of torque, gains a hundred or 2 kilos and is (naturally) much slower.
If you want to go sub 7 seconds you'll have to do something to increase the torque ££££!