I did a track day in a 355 a few years back, it was 'mildly moist' as the TG boys would say, and it was great fun, the acceleration, noise, the feel, everything… 8)
I'm sure the Audi would be fun, but a bit sanitised and TBH is that what you want from a track day? Aston, again very nice and lovely to listen too, but you'll hear it all day anyway as people will be using that the same day as your experience too. The only plus I can see for the California is the retractable roof, but that'll only come down if you catch that one day of summer this year…
Whatever, it'll be a hoot. Enjoy