Re: M & S considered "posh" and "high end"?
Higher quality than WHAT, exactly? I've shopped at M&S in the UK, and at *-mart here in the US. They are pretty much identical, on a world stage.
I've shopped in US "chain supermarkets" and on the whole anything in the UK is higher quality for food (meat and especially chicken in particular). On clothing side I seem to think I considered M&S to probably above Sears level and approaching Macy's. I definitely not put them in the same level as Wallmart.
That said, M&S can be a bit delusional at time. Remember after returning to the UK read an article about how M&S had sent a team out to look at US supermarkets and there were gushing comments about the amazing standards and varieties available in the US store they had just visited .... however, they'd chosen to go to Draegers in Los Altos (chain of 2 stores in top-end Silicon valley settings ... so had $200 bottles of olive oil on the shelf etc when we occassionally visited) ... rather like someone from the US commenting on the food stores in the UK on the basis of visiting Fortnum and Masons!