In terms of "above the call?" or in terms of "above the competition?"
Above the call: they graciously waived all the change fees and did not reprice the ticket when i had to immediately fly back home as a parent was having emergency surgery. It was a work trip, it was not insured, and this would have cost about $700.
Above the competition: superior IT for tracking luggage is first to mind. I have no fear checking luggage on Delta that it's going to get lost forever. Sure, i won't check a bag on a tight connection if I'm on my outbound leg, but I generally know that my bag has made its connection before we even push back from the gate.
I was Platinum in 2017, Gold in 2018, and as of 12/10/18 I'll be back to Platinum. I'm also BA Silver after four years as Executive Platinum, and I've had some kind of WN status almost every year since RR2 came out almost a decade ago. I'm a commodity to them, they're mostly a competitive utility to me in the way that Verizon is.