+1

However, I'm continually surprised by the standard advice regularly dispensed on internet forums that "Power Meters are for Racers only; they're a Waste Of Money if you Don't Race"

I would think the folks who could most benefit from a Power Meter are Cyclists Who Do Cooperative Group Rides.

Racers had been training and winning for decades before there were power meters. But for folks who have poor proprioception there is no way to convey the concept (much less the proper execution) of an Even Effort Ride without a power meter. Cyclists that like to go out for an energetic ride with friends where everyone wants to get a decent workout, take advantage of the benefits of pacelining, keep the group together...and yet often find themselves riding off the front, or getting dropped on decents... are prime candidates for a Power Meter.