I suppose this is a subjective thing, and varies from city to city, but I an tell you for a FACT that wait times are MUCH longer at WalMart than Publix in my area . I can take a stopwatch next time, just to prove it. Part of the reason is that the Publix near me is almost ALWAYS near empty. I suppose everybody is at WalMart or Kroger, but the Publix usually has MANNED checkouts waiting for me every time I go. I don't see how they stay in business. But it is a verifiable fact that, in extreme western Davidson county, the waits are MUCH longer at WalMart than Publix. Kroger is somewhere in between.
We count mullets when we go to Wal-Mart... Not so at our local Kroger.
I would gladly pay a tad more to experience a better atmosphere (no offense to the mulleted folks).