One thing I've been wondering about is what previous phones with fingerprint readers everyone has used (and hence, "trained on" for how to use fingerprint readers) - separating those who have no issue on the P6/Pro from those who do have issues.  The survey is conditional in that the answers of those who do have issues with the P6/Pro fingerprint reader are kept separate from those who don't have issues with the P6/Pro fingerprint reader.  I'm not tracking particular phone models, only brands, to keep things simple.