I’d be surprised if the ride and performance differences would be perceptible. Specifications are so close.
The extra dollars is really not all that much, considering the added new increased size power unit, and a dump bed.
The P500 served as a stout entry level SxS very well for Honda and it’s owners. However this new model IMO brings modernity to the entry level, and will attract buyers from competing brands, who have had a dump bed on their entry level units for years. I too can’t afford the next level up from within the Honda SxS lineup, the little research I did about the P500 and P520 led me to pursue the model that would keep me away from the entry level competitors. If the P520 didnt exist, most likely I would have the Polaris 570. FWIW