I bought the 458 very early on and even though this is my favorite car right now IRL, I got bored with it early on if that's even possible.
It performed so flawlessly in anything I entered it in so perhaps this is the reason. I have not upgrading anything yet (except racing soft tires and a full racing exhaust to spice up the engine note) so I'm sure I will be more into it when I start messing with it more. The 512 BB is more interesting to drive for me right now even though the stock vs stock performance doesn't compare.
I haven't bought the Scuderia yet so I can't really compare.