i dont get why people base their buying decisions on such numbers so much....its a no brainer.
if you look at the numbers again....the V8 reaches the more or less same level of power/acceleration at a lower RPM level and more important than hp..its the torque it produces which is higher than the V6...with less load on the engine.
All this means that you get a bigger and more powerful engine (so your conclusion that the V6 is more powerful is wrong)
Most lexus buyers dont have fuel consumption on their mind so if that is your concern...you are better off buying the V6 (i say this because it is cheaper to have a V6 serviced and maintained than a V8...and if u check the fuel consumption rating on lexus website....it is the same for city driving but you will be better off with the smaller one if you do mostly highway)
Apart from the engine and some minor features, the two cars are basically the same. The V6 model also comes with an AWD option...so check that one out.