What are the key differences between standard Audi R8 and the R8 Spyder?

I'm comparing the two models and want to know what sets the R8 Spyder apart from the standard Audi R8. Are these differences merely cosmetic or do they have a significant impact on performance and driving experience?

The R8 Spyder features a fabric top that can be opened and closed at speeds up to 31 mph, adding an extra layer of convenience to your driving experience.

Unlike the standard R8, the R8 Spyder lacks a rear window, making the engine and exhaust notes that much more prominent and engaging.

The R8 Spyder is slightly heavier than the standard R8 due to its convertible top, but its performance is still top-notch thanks to its 5.2-liter V10 engine and Quattro all-wheel drive system.