i've got an 04 rx300 and a 97 LS400, ok its not a gs and i've never been in a gs. i imagine the gs is nearly as good as the ls
but as comparisons go the ls is a far more smoother car although the rx has a more upright driving position which i prefer.
the economy is pretty similar, maybe better in the ls (around 22-25 mpg average)
you'll be in a higher tax braket next year(£400)
i find the 'car' is a much better car even tho its much older, it actually makes me appricate how good it is.
saying that the 'jeep' is fantastic but the engine does have to work a lot harder(the ls is 4ltr tho) and is noiser.
they are both great cars but if i was to only have one it would have to be the newest 'car'(LS in my case).
but dont be put off by that. i would rather have the RX than an IS or a GS!! as i go for looks and i prefer the RX above them two!
so basically i'm no help