iPhone Multiplayer: Authoritative or Non-Authoritative?

Dear CommUnity,

I'm creating a concept for an iDevice Multiplayer Shooter. Normally one would use an authoritative server, for controlling the gameflow and having some kind of anti-cheat-system (since players can't edit their positions/kills/etc)
However, a non-authoritative Server seems to be easier to handle and seriously: The iPhone is such a closed system I can't imagine how players could abuse a non-authoritative Server with this device.
Which kind of Server would you choose in my situation?

Thanks a lot,
Moritz