A friend of mind had a GS300 and it was pretty quick, but I was talking to a sales guy at the Lexus dealer yesterday and he was saying the 400 was the *BLEEP*!! He also said that comparing the 2 cars ( GS430 and GS400) he said the 400 was better. He said they were exactly the same car but 430 has a little more torqe but the horse power was still a stock 300hp. He said though becasue they took off the feature to the triptrinoc shifting on the steering wheel of the 430 the 400 could still beat it in a longer stretch. Beside I think having that feture weather you use it or not make the car cooler.