Tobias Schlitt offers a helpful hint or two for "speeding up" your application in the form of comparison operators.

The fact that type save comparisons (ala ===) are faster in PHP than the normal comparison operator (ala ==). The reason for this is simply, that PHPs loosly-typed-ness-auto-cast-code is not even touched with ===

He also points out an interesting condition that saves a bit of computing time - comparing the isset() of a variable to true over the count() to zero. Some of his benchmarking (code) shows this in action.