Great to hear on Battery Drain. I feel many other people aren't giving the upgrade a far shot because they don't go through the re-model exercise properly, or initially, and draw the incorrect first impression. However, there are some people saying their devices are heating up, and that to me means radio usage, or CPU usage. Either backing up / restoring to cloud or from Google playstore, or an errant program / a bad setting which didn't get set properly because they didn't FDR.

Call quality. Hmmm, I'll have to try my phone. However, Advanced Calling has been a rather hit-or-miss proposition for many, including Call quality issues, and Call disconnects / reliability issues. Everyone's MMV.