The thing with the Palmersport day is that it's all about the cars, as the track isn't very exciting regardless of layout. With Spa though you get the whole atmosphere too, and driving up Eau Rouge for the first time is an absolute heart-stopper of a moment. Combine that with the tactileness of driving a Caterham round the circuit and I genuinely don't think there's much that can top that in terms of pure experience, save maybe thrashing a classic 911 round the Ring.