I drove the G35x, but I just couldn't get past the styling of the IS. The G35 greatly improved the interior materials, but it still didn't compare to the Lexus. Great touches and features like interior lighting, auto dimming of the nav at night tied to the dash lights and light sensor (and not just a manual nav setting), easy bluetooth, buttery leather, etc.
Keyless system is GREAT, bluetooth, vented seats, nav.
Memory seats should have been standard, or at least available with a lesser pkg than the Lux Pkg; mirrors should have turn signal lights; console storage should be better.