Hybrids are better in every way. Batteries dont need to be replaced for a very long time and toyota usually stand by their batteries if anything go wrong.
I think one problem to check for but is inverter leaking. Its pretty rare but its happend, just a heads up.
Keep in mind, the rx400h will average around 24-27mpg. Thats horrible for a HYBRID. But you have to consider the fact that its basically a v8 due to the main engine being a v6 powered by two electric motors that gives the car strong torque. You can average 29mpg if you know how the car works.
Also consider this, the rx400h is lexus first hybrid vehicle. It took them years just to develop it. Once you know that fact, you appreciate the car alot more. It was the first.
To sum it up, you shouldnt experience to many problems with the hybrid system. Its like a regular car that needs things like new rotors,brakes,synthetic oil, auxilary battery, cabin filters, hid bulbs, expensive tires, etc etc.
I own a 07 rx400h an took bad care of it but its still going strong. Im going to buy another withvlower mileage in the future and take good care if it. The cars styling does not get old
