Maybe I grew up differently, but I care more about winning than a fast time. If Flatt runs 1:48 and wins a national title and Sumner runs the national record getting 3rd-4th then I would say Flatt is better and I would rather be Flatt than Sumner. Especially considering how the current 800m national record holder performed after high school. For those that don't know, Granville was potentially the biggest bust in the history of US middle distance running. He won two national titles on relays in college so that's cool, but that's just being part of the team and nowhere near the expectations out of high school.
Flatt focusing on winning tells me he has a bright future and Sumner chasing times indicates he will flame out and be another middle of the pack US runner who enters these set up A standard races to chase the A standard year in and year out but never wins anything important.
Here's some wise words: If you win every race you ever run, you will run a fast time and get a pile of global medals in the process. I'd bet Centro subscribes to this statement.