It's interesting that Airbus doesn't even mention EPR setting for unreliable airspeed or severe turbulence (IAE powered A320s) and uses N1 instead, even though this is said to be primary thrust setting indicator.
My personal opinion - EPR information is very nice to have, but N1 as primary thrust indicator/setting wins hands down. Very few failure modes and very reliable. In the very rare event that you have some engine damage (bird strike etc.), you could always refer to EPR that could give you some more clue.