Advantages
Kid,
There are advantages to both, and that really is why there are both. Typically the need for the autotune isn't required in the PLC, because the PLC controls the whole process, and at time the desired response from the loop controller is specific to the process. I've personally never used the autotune on the PIDE. Usually, if anything, I've seen PLC PIDs tuned to be overdamped, due to other conditions that made the overdamped response from the PID ideal for the process.
Russ