Retain types of non-outlet properties are a function of *ownership* not performance. The code will not run if the objects are not owned.

"There are no percievable performance differences between the two" is an invitation to remove the ambiguity of perception. Assumptions are dangerous and should be challenged.

The source statement of "Since iOS 6, views are not unloaded anymore, but loaded once and then stick around as long as their controller is there. So strong properties won't matter. They also won't create strong reference cycles, since they point down the strong reference graph." is a non-authoritative statement being made by someone who does not appear to be an iOS runtime engineer or have significant proven reputation in the community to make this kind of assertion.