Therein lies the screwyness. Zwift is averaging something else in, because on my first test, my 20 minute effort was only 140w, and they UPPED the number to 155w. If it was simply 95% of that effort it would have given me an FTP of 133w. That is the number that would represent the compromised FTP.

I think the first FTP was very close, actually. Using those numbers all of the HR zones and power zones matched up perfectly, which I wouldn't have expected if my FTP was off by much at all.

Also, in real world terms I've definitely made an improvement, because now I'm not getting dropped on group rides, and I can maintain higher speeds for longer.