Property vs. ivar in times of ARC

Question

If a variable:

1. Is declared in a class using ARC.
2. Is used solely for class implementation (not exposed as part of the class interface).
3. Does not require any KVO.
4. Does not require any custom getter/setter.

Then it is appropriate to declare it as an ivar without a corresponding @property/@synthesize, and to refer to it directly within the implementation. It is inline with Encapsulation to declare this ivar in the class implementation file.

// MyClass.h
@interface MyClass : ParentClass
@end

// MyClass.m
@implementation MyClass {
    NSString *myString;
}

- (void)myMethod {
    myString = @"I'm setting my ivar directly";
}
@end

• This ivar will be treated as __strong by the ARC compiler.
• It will be initialized to nil if it is an object, or 0 if it is a primitive.

You can't use KVO and do custom getter and setters with instance variables other than that they are very similar when using ARC.