I don't consider Peyton and Eli real, totally authentic, 100 percent Orleanians. I can't totally put my finger on it. Part of it is that the kids are part of the Uptown establishment and went to Newman (see above, and I understand and probably deserve the bashing from Uptowners and Newman grads).
Part of it is that the kids have names like Cooper and Peyton and Eli rather than Buddy or Skippy or Hap.
Part of it is the accent, which may have traces of Uptown but which is just so different from what you hear in the city (we will not hear Peyton tell the female sideline reporter after the game: "Darlin', when I threw that pass, I just said, 'Oh my Gawd!'").
Part of it is the college choices and the feeling that LSU was never a serious option for the boys. Cooper and Eli went to Ole Miss, a decision totally understandable given that mother and father attended Ole Miss (and a popular choice of Uptown kids). But Peyton's Tennessee choice--not LSU, not even Ole Miss, but another SEC school--rankles still.
In summary, the Manning kids, especially Peyton, are from New Orleans but in terms of culture are not totally part of New Orleans. Indeed, in terms of culture, they probably are a tad more from Mississippi--in speech, in manner, in outlook--than from New Orleans. And the reason is Archie and Olivia are from Mississippi, and the family's roots are there.