Dave, I've tried Wal-Mart charcoal with mixed results. For shorter smokes like ribs, it seems okay at best. Works okay for grilling too, but just okay. I had to fire up a chimney-full about 8-hours into a brisket smoke during late summer to keep the temps up. Wasn't happy... Kingsford just seems to burn longer and better. How much do you save when you have to double the amount of coals you use?
Of course, your mileage may vary...
Peace. Out.
Alan