it can really help lower you cost before the !!!! hits the fan(in the engine).
For the PT6 , there are speciall courses that are free that will help one in how to evaluate the collected data and when to take action if the trend moves. Probably,there is courses for other engine brands as well.
A fatal disaster happened to a King Air 90 down under some yrs ago, and they blamed that no one in the company could interpretting the ECTM correctly.