when he's on the floor. His off ball movement creates good spacing and he passes well on O too.
On the other hand, you can't be so married to advanced stat's that you're changing the line up every game or half based on advanced stat's. There's also value in continuity and building team chemistry. Players also have to feel trusted to weather the peaks and valleys of their performance w/o fear of being pulled at the slightest dip in stat's.
Some have shown concern that's what happened with Payton's PT and it's a valid concern given how that sort of thing can get in a player's head and make matters worse. There's got to be some balance of all those things. I just know what I see when McKay's on the floor and I really like him as a player for many reasons.