AnzialHeavy copper is great for saute pans and fry pans but of limited utility for stockpots. The thing is going to be filled with water, 2.5mm copper is no better than the flimsiest cheapest sheet steel.
Buy this thing if you think it looks nice. Don't buy it if you think it's ugly or if you think polishing copper is a pain in the ass. Or I guess if you plan on using your stock pot as a frying pan, then I can see why it might be that important, but those are some awfully high sidewalls.