The test to me is M&S on Waterloo Station. At 6pm it seems the world is in this slightly claustrophobic but big enough supermarket. There is one queue (as there

The test to me is M&S on Waterloo Station. At 6pm it seems the world is in this slightly claustrophobic but big enough supermarket. There is one queue (as there should be) and it is a steady walk. At the end are a big array of self service tills, always several to spare, and several staff guiding people. Something that feels like it should be a nightmare is actually a good experience.