What's your view on the Trinity? Missingno., Misdreavus or 'M?
...Do you have a violet or crimson aura?
Anyway, the Pokémon in Alpha Sapphire tend to be more passive, but frequently more subtle and poisonous, etc., while the Pokémon in OR tend to be more straightforwardly offensive, as the name might suggest. If you have a bias towards fire-types, such as Charizard, then you might want that one, otherwise not quite. If you have a bias against them, go with the one where you catch Kyogre. That's one of the main differences between games, and any particular differences in the progression, so figure it out from there in terms of which you'll be playing. If you particularly want both a Sawk and a Throh, then you can trade, but that might be weird.