Only Igor has the right answer . . . sorry for the rest of you who have such high aspirations for the Altezza by another name . . .
I will admit, I love the Altezza/IS300 for looks . . . but all things being equal, the Nissan Maxima will have to stand as the superior. It's the natural order of things.
Besides that, let's do a minor comparison . . . the IS boast an inline 6 posting 215 HP whereas the Max brings a V6 to the table with a whopping 232 HP . . .
We all know that Nissan engineering brings about the most lethal powerplants . . . plus in this situation the Nissan already has a 17 HP advantage . . . even if both cars had the same horsepower rating, understand that the VQ30DE has been one of the 10 best V6 engines every year since its introduction . . . that's nothing to sneeze at . . .
Lastly Nissan power delivery is unlike any other this side of the Autobahn . . .
Nuff said.