s2k2k3, well done. Love the picture!
And yeah, that car is up to the task. When you think about how old it is, it's much more impressive than the modern Ferraris are.
But I love the 599 the best. Getting the Enzo to drive well has been a lot of fun too.
My answer to the question: which car, is to buy every Ferrari and use this event to tune them all. I've driven this event so many times, taking a moment to tweak the car most laps, and moving on to a new Ferrari when the last one seems impossible for me to make better.
Best Gran Turismo racing I've ever had. From GT1 to now. Aside from online races, anyway.