Just a follow up to my original post. Powerwall Support contacted me from my service request through the app. Their research shows each Powerwall now has a capacity of 10.3 kWh's. So 76% of original, and as they are quick to point out, above the 70% warranty number. I told them I was surprised at the speed of degradation over 24 months and will continue to monitor it. Thanks for all the responses.