Model S is definitely cushy in comparison. And much better in the winter, because the more efficient HVAC means you don't freeze. BUT...
Once you run out of charge, the Roadster effectively charges 50% faster at the same power level. That's because, being a small car, it uses significantly less energy than the Model S. If you're traveling on Level II chargers, it's much faster with Roadster. A 400 mile / 640 km Roadster would be pretty awesome, you'd do the vast majority of your road trip charging while sleeping in a hotel.
Once you run out of charge, the Roadster effectively charges 50% faster at the same power level. That's because, being a small car, it uses significantly less energy than the Model S. If you're traveling on Level II chargers, it's much faster with Roadster. A 400 mile / 640 km Roadster would be pretty awesome, you'd do the vast majority of your road trip charging while sleeping in a hotel.