No, the Altezza is better. Welcome to GTPlanet, leppy.
You have 450 hp, but what else do you have? How is that power getting to the ground? Tha Altezza tends to slide around a bit, so maybe consider dropping some power and improving your handling.
Also, try a search of the main GT3 board (which will also include the Settings and Writeups boards. Put "amateur altezza" in the box, limit it to subjects only, and see what turns up.