Lexus has always been cushy rides, but definitely not on the sporty side of the equation especially since our everyday vehicles are a C230 and G35. The steering is a little vague steering into curves. Acceleration is good at all speeds, but you'll need to get used to the way the engine buzzes from the CVT. Gas mileage has averaged 27 mpg w/cruise control active even around 70 mph on the freeway. On a recent road trip on very hilly terrain we still averaged over 27 mpg, light on the gas. Brakes are a little difficult to modulate because of the regenerative system. We preferred the ML styling and driving dynamics to the RX, but so far find that the RX400h is a very nice ride indeed.
Fuel economy for this size vehicle is very impressive with the hybrid system. The backup camera is awesome. The navigation system takes some time to learn but a very powerful tool.
The lack of an aux input and iPod adapter standard is a real put off. Dealership wanted $700 to install adapter, I demanded and got a lower price. More center console open storage for cell phones and misc. stuff. Noise level. Passenger use of nav system. Center stack looks a little cheap.