Get the quincy, I have an IR 80 gallon 2 stage and it's not that old, hardly and hrs and I just had to replace both the pressure switch and the motor, after some research found out that the motors on the IR's have a tendency to over heat, some have even caught fire(glad mine wasn't one)Leeson brand motors.
My IR had about 50 hrs on it when the 5hp. motor burnt out. My neighbor had the same thing happen to him with his 7 1/2 hp motor on his IR. Buy the Quincy.