New Orleans is kind of a historic college football town. Honestly, I'd vote for that. Geographically, it's pretty equidistant for members of both conferences, so that's nice.
Dallas exists in the only state that both conferences share, so there could appear to be some form of neutrality.
Honestly, I think we make more money with the Sugar Bowl and New Orleans because that game will just become a massive party and it's in a destination city that's great for hosting football.