Without wishing to generalise, I think Louisa has a point. Though I don't use M&S foodhalls much, I know people who will and based on current habits they're quite likely to get into their car if it's more than 500 yards away, whereas my elderly neighbours, who've lived around here for decades, walk a lot further than that to Iceland for their weekly shop. Not sure this is a plus or minus, but I think M&S food appeals mainly to single people - reasonably quality and no waste - or those who just want something in the course of their working day, so they won't be parking for long. Anyone who wants to do a family shop or bigger household stuff in the area would probably still head for Sainsbury's.