I understand this is a subjective question, so I apologize if it needs to be closed, but I feel like it comes up often enough for me to wonder if there is a general preferen
If the condition is just a check of a single value, then !value is quicker.
However, when the condition contains multiple value checks, I find it much easier to read value == false. Somehow it is easier to parse multiple checks for equality than multiple negations of values.