Yes I read that. I read his old review of FC-R9100-P too.
I tried powermeters from Stages and from Garmin which had so so so many problems and where eating coin cells which where drained because of the hardware issues these powermeters had. Then I changed to the shimano PM (despite of the DCR review) and was just really happy with it. Never had any issues with it and for me it´s perfectly accurate enough.
Is an accuracy gain of +/- 0,5 to 1,0% as important as some hundred euros for me? Nope.
Do the “problems” Ray writes about affect my training success in any way? Nope.