I'm considering introducing: if ([myInstance isKindOfClass:[SomeClass class]]) { do something...} into a piece of code that gets called pretty often. Will I introduce a significant performance penalty? In Objective C, is there a quicker way of assessing whether a given object instance is of certain class type? For example, is the following quicker? (I realize the test is somewhat different) if (myInstance.class == [SomeClass class]) { do something else...}