Are reinforced springs worth it?

Is it worth buying reinforced springs? What is the difference to standard springs?

Depending on the vehicle type, the difference is between 15 and 30%, which is demonstrably noticeable. And if you often travel with a trailer or drive in a carpool with 5 people on board, it's definitely worth it.
In addition to the standard suspension springs. BILSTEIN also sells the reinforced ones for selected vehicles.