At which Texas BBQ joint was biggest gap between best meal & worst meal?

Consistency is a real test for any Texas BBQ joint that doesn't automate the cooking process. Managing of the elements that affect how pit-/smoker-cooked BBQ turns out requires practice and skill. Sometimes, though, even the best places can have a bad day. Of all the BBQ joints you've visited more than once, at which one have you seen the largest gap b/w a good day and a bad day? In other words, which place had the biggest difference in quality/taste between your best meal there and your worst meal there?