Fday said:So, where is the data that, on average, incorporating a PM into the training results in better performance improvement? How is a person supposed to know before they purchase one whether they will be one of those who see improvement or one who will see more harm than good?
There is no data like that, like there is no data about using a stopwatch to improve performances. A powermeter explains things, but an experienced rider can get great results without. It might tell you when you did something wrong.
I think a rider, starting to use a powermeter, should initially continue his training like before and look for powerreadings that are different from your RPE, HR etc and look for an explanation.
Otherwise hire a coach who is experienced in these files as learning it all by yourself might be fascinating but is also time consuming (like posting on a forum).
Time is better spend on your bike.