If not used carefully EPR can give erroneous indications - i.e. leading the pilot to think he has a certain amount of power/thrust wehn he hasn't. Remember the 737 accident in Washington. The engine inlet probe was probably blocked and thus the EPR gauge over-read.
A good way to have the best of both worlds is to check both EPR and N1 especially during takeoff. It only tgakes a second or two and a "realistic" N1 should be seen to compare with the indicated EPR. This would probably have prevented the Washington accident.
Be careful with EPR - it can lie. On the other hand, engine speed is a good indicator of thrust/power.