It all depends. It is not recommended to purchase mass-produced pseudo-copper pots and pans — the lightweight, stamped stainless steel type with copper-coated bottoms. The buyer gets the headache of the genuine copper equipment (keeping the metal polished) without enjoying the heat distribution advantage. The copper coating that is used to produce this lower-priced equipment is typically less than 1/50 of an inch thick — and that is too thin to distribute the heat uniformly. Even the stainless steel is deplorably thin.
Authentic copper pots and pans, which are quite expensive, are excellent because the thick copper metal distributes the heat evenly throughout the base and the lower sides of the cooking utensil. However, if the copper base becomes mottled with black carbon deposits, the even heat distribution is greatly impaired and hot spots develop, turning a positive into a negative. This is why copper cooking equipment is not recommended to anyone who doesn't have the time and inclination to keep it clean and polished — and it is a chore, to be sure.
Another drawback of authentic copper pots is that they must be periodically relined with tin, an expensive process. The pan must be relined once the tin starts to wear away appreciably because if too much copper leaches into your foods, your liver won't be able to remove the excess from your blood. The results can be noxious. However, the amount of copper leaching from a few scratches in the tin lining shouldn't prove to be dangerously toxic — that is, if you minimize or avoid cooking foods that are high in acid or highly pigmented, which chemically hastens the release of the copper and its oxides. Finally, fat-based cooking (frying) will release less copper than water-based cooking (boiling, braising, and stewing).