I have a 96 ls400 and my mom drives a 98 gs400. The cars are not comparable. For instance, the ls400 is a nice car to drive around in and can get a little aggressive when it needs to. But the car's overall comfort is just amazing. The brakes seem gradual and so does the gas pedal. Now the gs400 in my opinoin feels tight going from an ls to a gs. But like previous posts have said they are physically smaller. The car drives more sporty. Its got balls, the 2 cars may have the same engine but man does it drive different. Also the handling is a lot better there is a lot less body roll in corners. Also when driving on the highway you can hear the road whereas in the ls you cannot. I don't know if the new ls have this option or not but the gs has the shift on the steering wheel accessory and that can be nice for going around corners for fun. Also when you barely touch the brakes in the gs it starts to stop whereas the ls you have to push it down a bit. In my opinoin I like the gs becuase it is sportier, but my mom would drive my car anyday over hers becuase she just likes the comfort and luxury of the ls. But I have not yet driven the new ls430 with euro tuned suspension so that could change some things as far as handling. Good luck. Also the newest model of the gs400 is 1998 anything before that was the gs300 with the inline six, still a great car but with less hp.