The hammered copper hob is more resistant and durable, it allows quick cooking at very high temperatures, food does not hang.
This boiler: it allows a uniform heating at average temperature, the cleaning is much easier. Utensils without cladding in sheet metal: requires a baking with the first use, allows the caramelization of the natural juices of the food.
The inside of the copper stockpot is protected by a layer of tin.
The outside of the stockpot is hammered by hand.
Tin is softer than stainless steel and may wear away over time, but pans can be re-tinned inexpensively. Discoloration is normal with use, too, and should not be a problem.
It's available in many diameter (approximate):
12 CM - 4.7 INCH
14 CM - 5.5 INCH
16 CM - 6.2 INCH
18 CM - 7 INCH
20 CM - 7.8 INCH
22 CM - 8.6 INCH
24 CM - 9.4 INCH
26 CM - 10.2 INCH
30 CM - 11.8 INCH