Class schmass.
Waitrose has an ethical dimension to their business that other supermarkets do not have. Firstly it is owned by its employees, secondly it actually follows through on its ethical promises, unlike the bland greenwash from others. I have worked for the John Lewis Partnership and have seen the action behind their promises.
I believe the choices we make every day (like where we shop) build the world around us. Companies like Tesco and Walmart stamping on the fingers of their employees and suppliers so that baked beans are a penny cheaper does not breed happiness in the long term.
[/rant]
As an aside Tesco has just fought a long battle to open a new branch in Tenbury Wells (a small town near me). Everyone I've spoken to says "Oh I wish it was a Waitrose" Maybe that makes me middle-class with middle-class friends.