What criteria is he using?
Whatever makes him look good. I don't think he was 100% serious or particularly thoughtful. He was just trying to support his public image.
I suppose Americans have more and cooler stuff than we did 35 years ago, and if you're talking to an African-American audience having an African-American president might be taken as progress, but I wouldn't overthink this.
In terms of the economy and foreign policy Carter left us in a bad place and Obama (and Bush) have done the same, however one might want to tweak things to make one or the other look better or worse.