I think it's fine to just assign the instance variable. You lose the ability to modify the setter behavior (i.e., make the `attr=(new_value)` method do something other than `@attr = new_value` and you do have to be a little more diligent if you rename the variable or something, but in practice the first case comes up only rarely and the second case is mitigated if you write sane code and don't constantly re-assign the instance variable in a bunch of different methods.