It's worth the wait :)

Embarrassed to ask this but it's something I've ignored forever. Can you discuss the ins and outs of these scenarios?
a)
@interface
{
   NSArray* array;
}
@end

b)
@interface
{
   NSArray* array;
}
@property (retain) NSArray* array;
@end

c)
@interface
{
}
@property (retain) NSArray* array;
@end

Thanks for consider this topic.
-Phil

I'm not sure if there's much room to go in depth there, but the basics are pretty simple. For (a), you have an instance variable and that's it. No property, no accessor methods.

(b) and (c) are, I believe, the same (assuming you're doing a @synthesize in the @implementation in both cases) in general as long as you're on the "modern" runtime (64-bit Mac, iOS, iOS sim). There may be certain implementation-specific gotchas, like debugger problems and compiler bugs, with (c), but I'm not sure of the specifics there.