The Department of Energy recommends occupied setpoints of 70degF Heat and 78degF Cool. During unoccupied times, it is recommended to setback Heat to 62degF and setback Cool to 85degF.
If your system is experiencing problems "catching up" from a setback temp setpoint, you will need to adjust these temperature setpoints to allow for your system's capabilities as well as your individual comfort needs.
In short, you will have to find a balance point between your body's comfort and your wallet's comfort.
You also want to make sure you keep your air filter clean. If you have access to your condenser coil (the part outside), wash it down from time to time using a water hose.
I don't know what your location is, but I'm including a link from the state of Michigan which offers some helpful information and advice on how to keep your system running efficiently & effectively.
I hope you found this information helpful. :-)