I'm looking forward to an improved PIN unlock screen for those of us who are required to use a numeric PIN because of our corporate email. Since KitKat, the PIN entry keypad is terribly unresponsive.
I think it's dose because I'm pretty happy with the powersaving modes on my M8.
Android needs to come back to some more basic and good features which the phone vendors created differently in the past. This might help to reduce time for update cycles which really is getting a security issue now for a lot of phones.
I like the feature to control the Permissions. I am using a third party software to control permissions. but its not working properly.But i do not know when would i get Android M to my samsung galaxy S4.