That's not a terrible rule of thumb, but one can often do better. If you (the programmer) know that consistently correct prediction is impossible (as it is often is for binary search) then it's often beneficial to convince the compiler to generate conditional moves rather than branches. This is what the article shows for the test results.

Conditional moves (CMP/CMOVcc) will always be slower than correctly predicted branches (CMP/JMPcc) if the branch is predicted correctly. If the prediction accuracy if 50%, the conditional move will always be faster. The threshold for prediction accuracy differs for different processors, but 85% is a reasonable approximation. This necessary threshold is moving higher with modern processors (CMOV is getting relatively faster).