I have shopped in Wal Marts. The stores are dirty. The floors are never washed, there's a layer of grime over everything. The merchandise is stacked so high I can't reach things. I'm 5'7, average height, so putting things out of my reach is really dumb. The piles of merchandise have no sales appeal, except that they're kind of cheap.
The employees look like refugees from third world countries, which, I suppose, in a way they are. I have learned from long experience that it's best to shop where the staff is treated well. They are less likely to see customers as the enemy.
Grocery prices at Wal Mart are no lower than at the local grocery chain, and in that I don't have a family of six, I don't need a giant box of cereal, or a 5 gallon jar of pickles.

Sears sales staff always put the pressure on. That's the downside. The upside is that you will be waited on.