it is not OJ Mayo vs Ray Allen
it is New player vs (Ray Allen + Full mid level expception)
So those saying let Ray walk are missing some important info. We own Allen's Bird rights. That means we can sign him without using the MLE. Meaning we can get Ray as a terrfic sixth man and turn around and sign another high quality player with the five million MLE, like a quality rebounder for instance.
If Ray walks, we have to use the MLE on another guard to replace him.
So again, keep Ray: We get HOF guard as sixth man + five million to spend on another quality player.
Lose Ray: we have five milion to spend on Ray's replacement.