Just because Microsoft can implement something, even if it is relatively simple, does not mean they will.
Brightness profile? You kidding me?? Not that I would ever use the feature, just an interesting observation.
Miracast? Yes, I was told that Miracast is definitely possible, and was going to be on the 920 when WP Blue gets released. Upgrade 822 >> 920 >> 925, wait, does not happen haha.
Camera quality? They f'ed it up..
Loading times? Yup, that too.. It is a software issue. Might be the scheduler, cannot be for certain as I cannot test this myself.
There is a lot more than OS updates when it comes to adding a new platform for the phone. Microsoft has not given enough love to the S4 platform, and this is going to hurt all phones using it. This mentality extends to the firmware for Nokia phones ........
So yeah, I wish I would have known this was going to happen.
The extended support is great, but judging from the quality now, why in the hell would you want W10 on your 925?
I love the 925, so it will definitely be in my "Cherished but now forsaken" drawer.