Storing water in sliver or copper jug can sterilize the water after a few hours. This is due to the fact the these two materials have the property of releasing ions that kills the microbes. This property is known as oligo dynamic property. Keep in mind that cooking food in copper vessels is not a good idea as it causes formation of toxins that can harm you. Also copper is a best conductor of heat amongst "affordable" metals which is why copper vessels were used for boiling water long ago. Now its place has been taken place by stain less steel. In this age of technology we no longer need copper or silver jugs to sterilize our water when we have UV and RO filters which are safe and harmless contrary to popular belief.

Clay jugs just have the property to keep water cool. They used to act as water coolers of the by gone era, they can reduce the water temperature by a few degrees lower than the room temp. Since the clay jug is slightly porous some water passes though its body and evaporates .As the process of evaporation occurs it takes away some heat from the contents of this jug thus causing cooling. Don't try this by the way. Most us are not used to drinking this water and lack the resistance that our elders you might get a sore throat ( I know from experience I used to try all these experiments when I was young). its possible that in the clay jug overnight some microbes might breed, which could cause a minor throat infection.

Stainless steel and glass jugs are now used cause they are cheap and modern alternatives to the no longer required copper,silver and clay jugs. we now have water coolers/fridge and aqua-guard

TO FINALLY ANS YOUR QUESTION : it really makes no difference from which jug you drink your water as long as its clean drinking water that has been filtered.