John Gallagher over at the Big Nerd Ranch Blog dishes out the last word on the
properties vs. ivars battle:
Using properties has some very tangible benefits, particularly when it comes
to debugging: they provide a single place to set a breakpoint on access or
change, they can be overridden to add logging or other functionality, etc.
Many of the answers that give some preference for ivars express concerns
about the performance overhead of properties. We believe that the overhead is
insignificant for most applications, but thought it would be fun to prove it.
It’s full of benchmarks and discusses how the ARM NEON Engine changes
the future of this debate.