Nothing wrong with bulk oil. It's the same oil that's in the jugs. Now how long has it been sitting there,covered properly,exposed to the environment are variables I cannot control and answers I don't have.
If the shop is busy and those drums are drained lets say monthly then I don't see an issue however I don't know,but I do know that when I open a 5 gallon pail or a quart bottle that the oil is fresh,clean and not contaminated in any way(unless it happened before bottling).
This is where I would trust a mr lube or great Canadian oil change. Their reputation as well as handling and storage methods have a routine to them. And they do enough oil changes that the turn around on a drum is pretty quick.
I have personally seen a privately owned quick lube place have a trough and drum that all the empty quarts are hung on to drain completely. This trough has dust and dirt in it and the quarts wash it into the drum marked 10w-30. I am certain the oil in that drum has grit and dirt and whatever in it,and its pumped into people's cars. I've told everyone I know not to go there once that practice is sheer stupidity,and until that sump load gets filtered there is grit circulating in the customers engine. It's guys like that that give all quick lube shops a bad name.
OP. it comes down to the shop and their practices that determines what kind of shape the oil in a bulk drum is in,because it left the refinery or the blender identical to what's in the quarts and jugs.
